What I suggest is just make Rex a nuke carrier like a Nuclear Sub. The advantage is he can reach in-land targets over any terrain. Keep tactical nukes the same, bombard range 6 (unless your map is truly enourmous and you want to scale that up appropriately), that way you'll actually have the need to load them into Rex and have him carry them over. And while you're at it, best give Rex, and the Nukes he carries, Hidden Nationality.
Gee, I should know this, does SDI shoot down tactical nukes too? If it does, that sucks, makes Tactical nukes useless except that they cost $200 less, which is really only $60 less when you put in the Nuclear Sub (which can always encounter the good old 'getting sunk with nuke aboard' syndrome). If it doesn't, that's perfect for representing Rex's rail gun beauty, ie:
SDI:
Is that a CHALLENGE!!!?
Rex:
Yeah, try finding, tracking, and shooting down a warhead, travelling somewhere between half and close-to the speed of light, with no exhaust, fired from any random location on Earth.
ICBM's might seem cheap that they can hit anywhere in the world, but that's the point of building them, and that's what they can really do. That's what the Cold War was all about of course, both sides could use this 'cheap stuff', making it not so cheap. Then in MGS Rex came along, now you can't tell who's firing, so you won't know who to shoot back!
Anywho, got the back of Rex done, working on the Radome, then that uber rail gun, and then it's animation time!
