Not familiar with FF:Tacticts, sorry not really into jRPGs, they are boring.
XCOM is not an RPG at all, yes the newer titles do have some RPG elements, but the principle of combat is entirely different. And btw XCOM:Apoc had insanely OPed gas grenades early on in the game, so you're wrong, there was CC.
Ogre Battles - what is that anyway, some indi trash? Sorry for being harsh here, but haven't ever heard of it, not speaking of playing, so don't even see a point in googling what that is.
Oh, and the point of elemental combos is to do _FREAKING_ crowd control, which _IS_ CC! Even blowing the heck a gas with fire is crowd control. So you are providing a point you on your own are controversing. Google the definition of "crowd" and "control" for starters.
Yeah, electrified water and ice were an easy cheesy combo, however you wouldn't be able to win more then a half battles on Tactician in OS1, without using them. That's the whole point of the game, holy crap, and you're complaining about it.