Damn, that's one op tank (Mammoth Tank) lolz.
Prlly should make it so you can only get 1 of those new units.
Hm... I remember the Mutants and the Tiberium monster thingies from Tiberium Sun and thinking I'd like to play as them, but they would definitely not fit into Red Alert
Hm... how about a Moon Team? You know how they had those Moon based infantry? You could expand on that, make a race of some Moon Alien units and crap like that. Then make it that they are under contol of another terrorist group with Moon Launches and crap (so the infantry come in).