i mentioned this earlier, but no one seems to have picked up on it. so i will repeat:
i will now proceed to give an example of why you might need recoil compensation on a PAC. this is presented as the rules are written... you may disagree with some of this, and you are entitled to disagree (and houserule if you are the GM), but it does work, as far as i can tell (well, at least they never really indicate if the PAC is bigger than an LMG... it is my understanding the PAC is, in fact, handheld, albeit 2 hands, and is not intended to be fired from a prone position, based on the fact that it has no bipod, or tripod, built in, so i would rule that it is about the same size as the LMG personally. YMMV).
1) start with a yamaha growler.
2) install 2 weapon mounts
3) mount a PAC with a smart firing platform into each weapon mount.
each gun can fire in the same round, because it is the smart firing platform that is doing the work, and performing the actions. because they are mounted on the same vehicle, they still cause recoil onto the other.
if you really don't like this example, then consider the possibility of two people riding the same growler. each has a PAC. each fires the PAC. does it not make sense for their recoil to affect each other? the sudden shift in balance, at least, should throw off the other rider's aim. admittedly a house rule, but it is one i think not too many people would argue with.
of course, you could also just assume it's for dual wielding dragons