I tried to see what was wrong with the B7 in battroid mode.
If you change a little the animation to transform you may get a better proportioned B7. I circled in red, the piece that attachs the body to the legs need to move a little down, the problem i guess it will be floating, just put anything there to make a connection to the body. Also the upper leg needs to get out a little more from the lower leg.
Don't know if you already changed, the gun needs to be bigger.
I tried to do it well but those linearts didn't help much. Maybe i will give a try Frontier or Galaxy, they are already CGs.
Yeah.. would be nice...