Peaceful solution tries to be solved, but Starscream comes and messes up that plan.
Decepticons send all their forces planetside; Tidal Wave (giant carrier) lands in the sea, as wet-navy forces seem like they'd get the shaft in an era with spacecraft; the important Cons transform and fight their way to the sea with Starscream's group and dropped drones acting as support. Some drones are left in the city to act as sleeper cells in case distractions are needed.
Construction of Space Bridges starts, first by the Cons, then by the Autobots.
Inconclusive naval battle between NUNS and the 'cons.
NUNS sends men and materiel through space bridges back to Cybertron, with the intent of bolstering the resistance there. This introduces the female Autobots and Shockwave.
Megatron arrives with enough forces to do a space battle. NUNS had been planning for this eventuality, and Sheryl and Ranka call up two fleets of Vajra. Megatron's army gets forced planetside, to take advantage of the fact that humans need habitable environment but robots don't. He seeds the planet with mechaforming "stuff" (hadn't decided what to call it yet).
Decepticons are contacted by Galaxy remnant to help them control a Vajra fleet. They agree and launch a decapitation strike against the two Vajra fleets, creating a scenario like that one Starcraft mission - while one fleet is berserk and NUNS and the other fleet is trying to control the situation, another Cyborg Grace is loaded into the other queen to take control of that fleet. However, Dreadwing ('con) is supposed to escort her, and hijacks her instead, which now gives the 'cons another fleet to throw around.
In response, a NUNS-Autobot task force seize a Decepticon space bridge and put a fold bomb through it, saying that while the 'cons can wreck their planet, NUNS can do the same. The Decepticons hesitate, and another such raid happens (at a point guarded by Starscream). And then the next Macross fleet from Earth shows up. This prompts another negotiation, the purpose of which is supposed to be non-intervention between NUNS and the Decepticons.
this is the gap that i'm not sure how it should be filled.
It should conclude with everybody ganging up on Unicron, who has adopted Starscream as his minion. Enough bots and cons die that the ones who decide that they can live with each other after all, because this is Macross dammit, peace always finds a way.