I agree.
For the very small size of the control room you have and absolutely no acoustic treatment...not sure how well your monitoring/mixing will be.
I know it's probably tool late...but when you don't have a large space to work with...doing one big open room instead of too small rooms is a much better way to go, IMO.
Sure you have to use headphones when you are tracking...BUT...you have less issues with acoustics, and it's a nice, one, breathable space. Much more comfortable and everyone can see everyone..etc.
That's how I have my studio...and the single open space has never been a problem.