But the people that won't enjoy playing with 6 player wouldn't be forced to do so, they could play with 4 or 5 or 3 or whatever and enjoy the game anyway they want, just like we want to enjoy the game with 6, balance or no balance(Cheezus i hate that word, gamers are the most Yin/Yang Zen focused group outside of Daoism. ) .
Not exactly. If party size affects difficulty (no change to exp or combats), I (and the many other players who want a party of 6) can't play a Tactician-level difficulty game with the 6-person party. Because that difficulty would be balanced for a 4-person party (and thus would be too easy). Similarly, someone who wants to play an easy solo playthrough wouldn't be able to, because Story-mode difficulty would also be balanced for a 4-person party. We explicitly cannot enjoy the game anyway we want.
Whereas, if a given difficulty mode remains the same regardless of party size (scaling exp), players can separately select difficulty level and party size, fixing both of the examples I gave above.
Are you arguing for or against 6-party setup? Because the argument you used is used by those that want the game to maintain a 4-party setup. "No! we can't let people play with 6 characters!! What about the precious balance! it will ruin my game if someone else is playing the game "unbalanced". BTW, Hyperbole, but still pretty close to their arguments.
Anyhow. Yes! Of course it would be better if the game was built around your preferential party size, i am with you on that. But that is going to take much more time and manpower rather than just implementing a warning at the beginning of the game stating that it will probably become easier and a little less balanced if you choose a 6-party setup. Since 6 character party is already possible in the "tutorial", it just seems arbitrary and cruel against us that want to experince as many companions as possible to lock the party to 4.