I don't know which is the best but flourishes plus smites is always fun.
Yep, loved my swords bard/oath of ancients dex-based paladin of Eilistraee with flourishes for extra smiting.
But I agree any college can work, it just comes down to how you want to play.
I guess with a party of Karlach/Astarion/Wyll as the OP mentions, I’d perhaps be tempted to go for a more spell-focused lore bard as the companions can cover melee and if Wyll is staying as a warlock then he doesn’t get many spell-slots per battle so bard spellcaster would be handy for crowd control, AoE, buffing and some healing so you’re not totally reliant on potions, but given there are lots of ways to build and use those companions too, that’s by no means necessary.
