A party of 5 or 6 really allows characters to specialize and use specific spells, skills and feats. With 4, you need at least 1 tanker if not 2, a rogue, a cleric (or "medic" in general), there is little room for anything exotic.
Yeah, we talked extensively in the other thread (you know, the popular one, the one in FAVOR of 6 men).
That's precisely what I hate about the 4-members limitation.
Party control in Baldur's Gate 3 is a complete mess that begs to be addressed. SAY NO TO THE TOILET CHAIN