Remaking Dragon Emblem

My current Dragon Emblem team isn’t finished, but the current team I have needs some work.

My team is currently
Adult Tiki (+Def -Res)
Myrrh (+Atk -Spd)
Corrin (+HP -Spd)

I am thinking of replacing Corrin with Nowi, or maybe Ninian if I’m lucky enough to get her.
Then, my fourth member will hopefully be GRobin if I can get him.

Should I replace Corrin, and who should the fourth member be?