Thank you guys for the quick responses!
Yeah I guess I haven't explored Virion enough, he wasn't ever really used the last time I went through Apotheosis (2 years ago lol)
Haven't tried out Cherche x Henry but that'd be worth exploring. That frees up
Chrom x Sumia
Lissa x Vaike
Sully x Donnel
Cherche x Henry
Tharja x Gaius
Nowi x Kellam
Miriel x Gregor
Panne x Virion
Olivia x Libra
Cordelia x Stahl
Maribelle x Lon'Qu
Male MU x Lucina
Switching things up a bit, differences are Kellam!Nah, Henry!Gerome, Vaike!Owain, Virion!Yarne. I still haven't used Ricken but I've seen most people swear by Gregor!Laurent for Armsthrift, although Ricken!Laurent turns him into a crazy Sage. Fathers for Owain and Brady are giving me the most trouble, although I didn't use them too much my first time around.