As Kup would say one Decepticon is one too many. Each Decepticon is stronger than the average Autobot. It makes sense that the Autbots would use teamwork to win. Looking at the larger cast of Autobots it seems evident to me that they would be grouped to face a massive assault of Decepticons. Main Team- Optimus Prime, Bumblebee, Ratchet, Bulkhead, Prowl Second stringers - Arcee, Blurr, Wreckgar Cybertron Elite Guard - Ultra Magnus, Sentinel Prime, Ironhide, Jazz Dinobots- Grimlock, Slag, Swoop
I am sure when Megs gets a body and rallies his troop, we will see a massive battle with all the 'friends' the autobots have made on earth. And the power of good and love overpower evil and hate! Go Love!
I think the finale at the very least will be a huge battle involving everyone. I'd even hope the human villains will show up to help, reasoning that they stand to lose big time if the Decepticons win.
Personally I would count Ironhide as a 2nd Stringer, instead of a part of the Elite Guard. We don't know yet if he is a part of the Squad or not (we haven't seen a photo of him that shows that he has an EG logo).