Alright cool, you got me with the balancing vs time argument. I'm not even saying it needs to be in. But I'm agreeing with the folks that wants it as an option anyways because, why not? Just make it a clickable option in the option menu.
They chose that number to balance the game around it already. Cool.
All I'm saying is that the game could worked with 5+ as you're technically already getting 5+ in quite a few fights already as well. It goes back to the whole people should play how they want argument.
I'm not sure how hard it is to code in a script that have a few extra trash mob with the generic some some Archer and so on popping in during combat or tweaking exp and than some to compensate for those who want higher difficulty, but shouldn't that choice come with the difficulty setting already? Different settings down the line for different gameplay choices?
But I'm pretty sure it's a very possible thing to do, where you balance a game around a party of more than 4.