But the game does not grant you the tools for that. Yes, there are mock battles, which get tedious.
Some kind of score, synergy visualization or maybe a predicted turn and action order works have helped so much.
So in the end I am building my units in a way that makes sense lore wise, disappointing

The overworld gets really overwhelming, specially when starting out.
So many characters! So many classes! Those are actually good things, what brings me to:
So much wasted potential!
Hear me out, I really want to deep dive and explore class synergies. Build unstoppable teams.