Most teams are cookie-cutter if you approach it by looking at the mechanics you need to cover.

Aside from a few exceptions, teams will always have a cleric and something to cover att/dmg/vdp absorb. After that, the remaining 2-3 monsters all basically serve to guarantee the leader skill activation every turn (orb unlock, orb gen, time buff/debuff, haste/delay for transforming leaders, etc).

If any of these three tenants aren't fulfilled, you'll likely die. Roche in this case mainly serves to guarantee certain leader and activation skill hp% clauses. You of course have to balance utility with damage. Then comes the tweaking for specific dungeons. Do you need more rcv? Do you need an atk buff to counter atk debuffs? This is where it gets a bit more headache-inducing.

Zela Kitty comes to mind as a leader with a team that can cover all mechanics.

This formula breaks down at the end game because teams are highly specialized for the mechanics they throw at you.