+1 to having a 6 party team. 5 could work (perhaps) but a 4 person team is too restrictive. The current size forces you to pick certain characters so you have your bases covered (rogue, caster, cleric, tank). No room for a bard, ranger, monk, etc. in there.

If the intent is to choose characters for your party because you like their personalities, then they're failing at that. I'm choosing who joins my team purely on what my PC's class is. E.g. if I'm a rogue, i'll drop Astarion but keep Shadowheart (cleric), Gale (mage), and Lyzael (tank). I could probably sub out Gale and Wyll but the others are locked unless I change my main class.

I suspect part of the issue for Larian is the effort with creating new party members (voice lines, choice & consequence, etc). Wasteland 3 had a good solution for this - you can have 2 companions, and 4 player made characters. Maybe the answer for BG3 can give you 3 player made characters and 3 companions, or some variant thereof.