yummysoap wrote...
Despite contrary belief I don't think ME3 is really going to be about gathering allies against the reapers precisely for the reasons Shandepard has mentioned: the only dudes who have actually come out and stated that they want to take down the Reapers are Cerberus and the Rachni (and Liara in LotSB). Everyone else is either in denial or doing their own thing. Also, yes, at the end of the day it's a third person shooter, not a flight sim, so unless 90% of the game is just silly running around doing things irrelevant to the plot and 10% is allied fleets kicking Reaper ass (which I'm sure everyone will agree would suck), I don't see it as all that likely.
I expect it might be a little of both. Some allies you go around recruiting right as the Reapers approach (likely the more amiable ones who simply weren't preparing as much, such as Krogan, Rachni), while as the story progresses more and more of it is fighting against the Reaper's first waves. So, say, two allied recruitment missions, a first contact with a Reaper force itself, followed by another recruitment/rescuring a beleagered would-be ally, followed by another direct conflict, and then rescuing a reluctant ally like the Council...
That said, your allies will probably impact the invasion to some degree, but I don't think it'll be game-changing or game-central. In all honesty, sad as it is to admit it, I can see Shepard spending ME3 preparing for a seemingly hopeless fight until an old reaper-killing plot device awkardly launches itself into the game (probably something to do with "dark energy" and Haestrom, as that is foreshadowed in ME2).
My expectation is that while the war itself might not hinge on your allies, the course of it does. Reapers are everywhere, and to counter them at any given point you need a certain number of allies.
I strongly suspect, for example a sort of delimma in which the Reapers are attacking more places than you have ships/men to defend: say, the Citadel, Earth, Thesia, Tuchanka, etc, and you have to move to counter with your fleets. If you don't have the numbers, you can't cover them all, and so a 'hard choice' is who to leave to die... but if you have more/stronger allies, then you can save more people. Past decisions come back with a vengance.
So, for example, if you saved the Council, then the Destiny Ascension and a combined Citadel Fleet will defend the Citadel/Thesia for the Asari, but the Turians are left to defend themselves. But if you let the Council die, the Turians arms buildup lets them defend themselves, but the Asari are SOL. If you gave the Base to Cerberus, they defend the Charon relay, protecting Earth while the Alliance goes out and fights somewhere else. And if you spared the Rachni, you get an extra army for free.
Stuff like that.