Here are a few sheets with unfinished redesigns. The character proportions and head scale are about the same as in the Xexyz stuff.
As for X-Com, I think I'm going to have to revisit my Rebel Squad project and revise the designs. I think these kind of proportions with more curves is more dynamic, and I've changed my mind about real time vs turn based. One of X-Com's biggest strengths is character development, and in a turn based game you can maximize the player's exposure to the characters. I think, even if you design a real time system with multiple monitoring windows (for scattered characters), the player will have a constant nagging feeling of having to be everywhere at the same time with his eyes. It's not enjoyable to constantly be reminded that you might be missing important action pertaining to your characters. Being able to effectively deliver tasty little bits for the player to build his game spanning macro story with takes priority.
As for the cute cartoon style, I don't believe it would make the game less scary or involving. Horror is mostly music and build-up. Benny Hill music will make almost anything funny, and if you just walk into a grimdark scary movie it's not scary at all because you missed the build-up.