Hi, the Ra1 AI is pretty simple specifically in skirmish mode, they don't create teams or whatsoever, also don't expect they would use the Chrono Tanks, Tanya, and other special units the way they are meant to be used.
All the Ra1 AI can do is, ramdomly, create units, men, tanks, etc and in a random elapsed time, they all go 'all to hunt' mode which means they send all their stuff to randomly kill your units/buildings, usually starting with the Ore Trucks, meanwhile they keep creating more units, men, tanks, and in a random elapsed time you may receive a second wave, and even build some planes and copters in late game. That is the Ra1 AI exactly and it has not improved in the remaster.
I am completely unaware of any mods being able to improve the AI in RA1, I hope someone can sum it up.