Currently game present us that option:
1 Thief
1 Cleric
1 Fighter
1 Mage
1 Warlock

We have lack of options in Baldur's Gate 1 or 2 there was more space in party and mroe characters to chose. In Divinity Original Sin and BG 3 we are limited to 4 character but in DO we got option to change every of character in our party from scrach almost everywhere. So if Larian want stay with 4 characters we shoud get a lot more avaible characters in later game. Baldur's Gate 2 for example allow player to join 5 from 17 avaible characters to his party. This was enought to make really ncie setups for every kind of player.