both pathfinder kingmaker and wrath of the righteous allows us to play with all companions in 1 single playthrough. it's player choice who they want to bring them along and never lock them out so that you have to play 2nd playthrough. i like that idea. i concur. a party of 6 provide players more flexibility in how we want to play the game. we can even pick support classes as main hero if we so choose and not forced into having a min/max party. having more options means game will be more fun.
thing is i kinda feel larian design always wanted to give players some artificial difficulty and challenge by restricting players with 4 characters and then proceed with bombarding players with outnumbered foes. and the only method to play it is that players have to resort to terrain/height/shove/barrel exploits to win battles. i say larian should forget their old formula. pathfinder has difficulty without having to resorts to exploits. the way to bypass pathfinder difficulty is to learn the rules and mechanic.