I think the premise of the trade is similar to the SAC-DAL Richaun Holmes salary dump, at least the dumping Ball part of it. In that trade, SAC gave DAL a first round pick so that they would take Holmes ($12.9M) into a TPE they had from an earlier trade.
In the proposed trade, CHI is getting out of Ball's contact but instead of a pure salary dump, they are getting back a player (Brogdon) who can actually help them now. Ball is a bad contract due to injury, he is just taking up space on CHI's roster. Brogdon is not a bad contract, he is a good player who can help a contending team as a starter.
So if the price to dump Holmes and his 1 year $12.9M is a late first (it was actually #24 I believe), what is the cost to dump 2 years and about $43M Ball contract? I thought SAC gave a lot to dump Holmes, I think POR would be happy with 1 first to take on Ball. who may follow Shaun Livingston and find his way to some productive play at some point. Then the question is what is Brogdon worth? The Celtics gave up a first and some useful players (Nesmith, Theis) and that was before Brogdon won 6moY award. I can't see that he is worth less than that now.
I see this as a reasonable trade proposal.