The main factions are:
a local soviet council with soc-demmy tendencies reflecting the Soviets' canonically cooled-off relations with the US
Remnants of the Chinese government attempting to reunify an alienated eastern bloc before NATO can get back on its feet
A Makhno-esque black army that demands autonomy for the local people
The main driver of the conflict is control over a robotics factory that can be salvaged and converted into creating power armor
Later on you find out that the Enclave is stoking the fight by releasing capitalist super mutants, and the final climactic battle is set against a backdrop of a kaiju fight between Liberty Prime and a giant mechanized The Motherland Calls
How about instead it's Liberty Prime versus like ten salvaged T-34s, which wreck it from outside its effective range because despite being extremely old and outdated tanks they still have actual tank guns. That would drive home the point that Liberty Prime was actually overengineered rubbish that served no actual battlefield role and was basically just a terror weapon to unleash on civilians or unsupported infantry, and which couldn't stand up to any sort of combined arms tactics.
the kaiju fight is the most important part
I wonder what sort of military you could be talking about here.