Do you think that the Bucks have a priority in re-signing Middleton?
If they do (and if they want to they will), they'll put themselves in a financial bind after signing him and Bledsoe or another starting level PG. They would still need to re-sign Brogdan and Lopez, or replace with them starting level SG and C, and they won't be able to offer them big bucks without going deep into the luxury tax.
BTW, here is the stat comparison for Brogdan and Middleton this year
http://bkref.com/tiny/7wQ80 Like I said, Brogdan is undervalued. Give him Rubio's usage and the Jazz score several more points a game. Give him more shots, which he would probably get, and he could easily score high teens, but plays both ends of the floor.