That stat issue is something I also encountered in PF:WotR, where the main stat to pump for one character is intelligence (or wisdom, depending on background, 3.5e is extremely complicated when it comes to building), though.
RP-wise it's even right that a CHA based character is the face of the party, but I also feel a bit like "mostly it's CHA based classes for your main" here.
But I don't think addressing Larian is right, the problem lies much deeper in the D&D rules, which don't currently allow replacing CHA at least with INT or WIS (something that 3.5e allowed to SOME degree between INT and WIS).