Thinking about doing another run with a single class party. My first thought is druid, because between the subclasses you can get a good mix of healing, AoE, and tanking. What other classes might work? Is there enough gear to go around for this to work?
Boring answer possibly, but Fighter. Can have each different one lean into defensive, dual-wield, ranged, two handed weapons however you want. Can have one or two be an eldritch knight for magic too.
A lot of enemies in the game have resistance to the blunt, piercing, and slashing so the ability to do some kind of other damage type is important. Some kind of magic would definitely be welcome in a fighter comp.