All of that is exactly what I was thinking when I read your post above. I'd put the gunner up front as well and
who says the vehicle commander has to sit up front. He could do the job from a smaller tighter seat close to the two front seats leaving more room in the space in the back for extra folks or gear and would allow him better control of the dismounts in the rear and provide him with an easier exit with them.
Kind of makes you wonder why the folks at Textron didn't come up with all of that in the first place when they were designing the details of this thing.
I'm a firm believer in making the most of what you have. A little kit bashing can pay big dividends.