For most of FE7, I used Marcus as my strike-team. For FE6, I use the mercenary group gained in chapter 2, plus Lugh and Chad. For FE8,9, and 10, I honestly can't remember.
This looks like a really cool hack!
For curiosities sake, after you port all the features from FE4 to the hack, do you have to keep doing it per chapter, or is it just there, waiting for you to tile it?