I don't see why we need to compromise on this. A party of up to 6 could have a party size of 1, 2, 3, 4, 5, or 6. Let the player decide if they need the extra companions or not. Settling on 5 as a "compromise" seems arbitrary to me. 🤷
Then balance the game arround 5 so players that want to stick to 4 just have a little bit harder adventure while some that want to play with 6 has something a little bit easier.
