Coordinated Firepower states "Whenever a unit from a Hunter Contingent selects a target in the shooting phase, any number of other units from the same Detachment who can still shoot can add their firepower to the attack. These units must shoot the same target, resolving their shots as if they were a single unit–this includes the use of Marker Light abilities. When 3 or more units combine their firepower, the firing models add 1 to their Ballistic Skill."
That's it. If you haven't heard the arguments or haven't figured out just how impactful that rule is then I urge you to read it again and think about it for a minute. Let's break it down:
"Whenever a unit from a Hunter Contingent selects a target in the shooting phase, any number of other units from the same Detachment who can still shoot can add their firepower to the attack."Okay, so this is saying I can combine the shooting of multiple units against a chosen target as long as the units I'm shooting with are all a part of the Hunter Contingent. Cool, I'm intrigued.
"These units must shoot the same target,..."Okay, this is kind of obvious given what it already said.
"...resolving their shots as if they were a single unit"So they fire everything together as if they're one unit (but don't actually join together and form a unit). I get the point. Wait, what about if I'm using two marker lights to ignore cover, do they benefit from that or do I have to spend multiple marker light tokens?
"this includes the use of Marker Light abilities."Oh, okay. So I'm combining all the shots from the two or more units; I add the shots all together and treat them as if they're coming from one unit, including being able to spend marker lights to affect all the units shooting together. Okay.
"When 3 or more units combine their firepower, the firing models add 1 to their Ballistic Skill."Oh sweet! Gotta love these new formations that grant extra BS! (bah-dum-tiss)
So where's the confusion? Where's the over-powered 40k-ending cheese fest? Right in the part of the rule that says "resolving their shots as if they were a single unit". Several special rules in the core rulebook state "a unit that contains at least one model with this special rule [benefits from the special rule being discussed]" so when the shots are resolved as if they were a single unit, that unit contains all the models in it, and therefore any special rules those models have that are shared to their unit are also shared to other units pitching in to this coordinated shooting attack, per the rules as written ("resolving their shots as if they were a single unit").
Now let's keep that all in mind and look at the Target Lock wargear item from the codex:
"A model with a target lock can shoot at a different target to the rest of his unit."If its unit is participating in the Coordinated Firepower attack, this model per its wargear item can still fire at a different target because its unit is still firing at the target unit and thus fulfills the Coordinated Firepower's requirements "...these units must shoot the same target." The same can apply to Gargantuan Creatures who can fire each of its weapons at different targets, allowing it to toss in a single weapon to allow all of its other shots to benefit from the shared special rules and the +1 BS being handed out for three or more units participating.
Now let that all sink in and see where the fear-mongering comes in. You can have everything shoot together and get all the special rules, and then still have models firing at separate targets with all the benefits that are being shared. THIS is what people are complaining about. They're not whining about just being able to fire two or more units into one target enemy unit with the added benefit of a few special rules to make sure it's extra dead (and if they are, they're not getting it). What the people in charge of the tournament scenes would have you believe is that this is outrageous, over-powered, and not what was intended. I couldn't disagree more. Since at least 5th edition's inception eight years ago, this game has always had deathstars and flavor of the week power-house armies and codexes, though they are more prevalent now for sure. If you bring your competent take-all-comers Tau list to your local store and end up on the opposite side of the table of any of the big tournament lists (Centurion-star, Daemon Flying Circus, Daemon Summoning Spam, Scat-bike/Serpent spam, Jet Council, etc, etc, etc) you're going to be in for a rather unpleasant game regardless of how "powerful" the Tau Empire codex is perceived to be. The reason Tau are not listed on the top tables in tournament reports despite all the whining you hear about them on "teh interwebz" is because the army has its weaknesses (Multiple Small Units, any assault at all, etc) and good players exploit them. People are so lazy and quick to judge based on hearsay than actually playing the game and learning for themselves that now when someone on the internet cries "Overpowered!", the mindless group-think begins and you can't get a word in without someone accusing you of being a "WAAC" player or cheese-master, etc.
From everything I've read online, all the batreps I've watched, and the games I've personally played using the Coordinated Firepower rule, my personal experience has been that it isn't anything more than a cool buff Tau gets that falls in line with the other "Decurion-style" detachments each army is getting in 7th Edition. Yes it can be powerful, but so are all the other armies' mega-detachment buffs. If you are trying to min-max your way into taking extreme advantage of the Coordinated Firepower rule, what would that look like? How effective would that list actually be, both on offense and defense? How many models are in it? Have you built that list? Have you seen it played?
I just saved you time and deleted about two pages worth of army lists, weapon groupings per range, and the listed applicable buffs those units and lists had, but I realized a simple truth; to build a list in a way that breaks the Coordinated Firepower special rule, you're assuming way too much is going on in favor of the Tau before the game has even started. You're assuming all the Fusion Blasters are in melta range, you're assuming all the Plasma Rifles are in rapid-fire range, you're assuming all the Burst Cannons and Airbursting Fragmentation Projectors are in range, all while giving Tau complete line of sight everywhere, all game long. If that's the type of situation you find the Tau in when you play, you may need to rethink your tactics and strategies and consider if 40k is the game for you. You should never be in that situation against Tau if you're moving intelligently and utilizing target priority in your turn as well as playing with ample terrain (and this is coming from a Tau player, terrain is more fun for everyone). Trying to break the Coordinated Firepower rule on such a scale that it makes tournament organizers pee their pants is insanely difficult, takes too many points, too much time to plan in-game, and has too many issues with weapons being in range, at best.
Again, I find it to be a useful buff here and there that is taking typically four units out of action to annihilate one unit (one unit to fire marker lights, then three units to fire together with +1 BS and shared marker lights and USRs if there are any). Have your experiences shown otherwise? Let me know!
Also, I think it bears mentioning that despite Reece Robbins' best attempt at making strawman arguments and using one of his four source's opinions on how "overpowered" Coordinated Firepower is, just realize that Nick Rose, Ben Cromwell, Goatboy and also Rob Baer, and Matt and Dave from Miniwargaming all believe that most if not all of how Coordinated Firepower is worded is legal per the Rules As Written.
Again I think this whole thing boils down to fear and overreacting instead of critical thinking and play-testing. I'm going to keep on playing it how the rule is written, reading and watching battle reports, and checking out tournament results. I don't know if Tau has what it takes to make it to the top tier without allying, but with new toys like the shiny Optimized Stealth Cadre formation, I think it's certainly possible. Oh, you don't know what that is? It's only one of the most powerful things in the new Tau Empire codex, but you don't hear many people talking about that...
Overall, I say that until people have non-anecdotal proof and quit the fear-mongering and whining, people need to just