And here again I think you're all missing the point that I've been trying to make. All they would literally have to do to balance this game currently for a party of six is to use proper D&D stats for all monsters. If they just used proper stats, the game is balanced for six. I've tested it. I know it works. It makes the game so much more fun.
And yes, the big battles take some time, but in tabletop session, it took less time with a party of six then it does in the video game right now with a party of four. Same enemies. Proper stats. The reason is that you have a bigger party that can do more damage per round.
You, the player, having more characters to control during combat speeds up combat. It also means that you have a far less probability of losing a fight and having to reload. Reloading a fight is far more time consuming and frustrating.