Why would you want to hit the enemy ship from multiple sides?
The way the game is designed you want to try to focus all your fire into a single shield facing.
Any ship with MVAM could be more of a support DPS role than pure DPS role; the other ships in the fleet could easily open up shields and no matter where you are, you have access to the open shield quadrant. Tactically speaking, it can also improve overall damage output on multiple fronts; you have two sections pouding one quadrant while one section diverts fire, decoy-style.
I doubt we'll see it happen though as the AI on the ground being as bad as it is (with all due respect to the devs, I'm sick of seeing them stuck in doors all the time), I don't think we're ready for a MVAM just yet. Would it be nice? Sure.
But it would also have to have hefty penalties for it's use. I mean, one section blows up... what do you do to recombine the ship?
It wouldn't be any less fair than a Keldon spawning 2 photonic Galors or a Klink admiral in a Vo'Quv spawning fighters. It'd be fairly simple to add as the mechanics are already there as we see in the Keldon's in cardassian space and the klink carrier. Tweak the models, spawn 2 sections and have them attack independantly. The keldons photonic galors are pretty easy to kill though but mechanically, in principle it could work, and it'd be cool to have a fed ship that could spawn some adds the way the cardie NPCs and klink admirals do.
And what about fairness to everyone not flying a Promethius class?
As per any advantages, disadvantages would occur, obviously.
For example, since instead of having one shield around your one ship, you're going to end up having three more fragile vessels doing more damage. As per anything, it's a trade-off.
It really isn't unlike the current cruisers vs escorts vs science vessels. And not only that, but seeing that currently this game has only 3 "classes" (and even then, they all can do pretty much anything), it would allow branching gameplay, which could open the doors to further classes and specializations.
What about fairness?
No game is ever fair as there will always be something that someone else will have that you wish you had for your own class.
Damn those cruisers with 4/4 to my 4/3 escort at admiral level!!
I would think the other problem with a ship splitting into 3 different sections for whatever period of time would be power management. When you have one ship, you have one shield generator and one energy pathway to get to the multiple beam weapons. If you split the ship into three sections, suddenly you need three shield generators and the two sections without the warp core are going to need alternate power routing to power the beams. That also implies another issue in itself: Shields and weapons require significant energy to power them, presumeably from the single warp core, which is why you can buff them only with a substantial loss to speed and auxilliary systems. If you seperate the ship, the other two sections do not have access to the warp core to provide power and the impulse engines are wholly insufficient for the task (note: you would need three impulse engines as well, unless you only wanted manuvering thrusters and that seems like suicide).
Also, having the ship split into three would make for a much easier target to take out than if it remained whole. For example: It is significantly easier to take out three AI Bird-of-Preys than it is to take out a Neg'vahr, and that's with them each having full power from a warp core, which you would lack...
The version of the Prometheus in Voyager, where it first showed up, was a prototype. The muti vector feature was deemed too dangerous and impractical. That feature in the Prometheus was designed out of the final production space-frame as a result. Saucer separation is used for emergencies only.
This is the "hand down" from CBS to Cryptic. I read it here on the old ships page. The bit about it not being feasible is from a developer interview some time back. I can't remember who. I want to say Jack, Maybe zink, but I am not certain. From what i recall from that interview whom ever it was said they messed around with it but it simply didn't work for the reasons I cited.
As far as Canon goes, given what I have seen over the last year, STO is best classified as "medium" rather than either soft or hard canon. STO obeys hard and ignores soft and can be taken as hard or not at all in future development of the core IP. So, until we see something contradicting this MVA issue with the Prometheus in confirmed hard canon, it probably should be taken as "firm" if not hard.
As an interesting aside... I remember seeing in one of the videos Cryptic released a separated galaxy class. You could clearly see the stardrive section without a saucer, and a saucer nearby. So it appears that at least at some point in the development, ship separation was in the game.
I'm sure there was a good reason why it was removed, but at least there's hope that it could be re-implemented in the future when they have more time to work out the details.
I'm guessing the way it would work is you'd take control of one section and the other one would fly around like a pet attacking your target with you. It gets kind of problematic though if one section gets destroyed...