Our ceiling is capped with Rudy eating 1/3 of our cap my guy. You said perimeter defense was our problem and Simmons is the best perimeter defender in the league. Critical thinking is not something you do a lot I take it.
Stay in your lane.
Let's use the critical thinking
Pros:
1) Best perimeter defense in the league. Switchable 1-5
2) Has the size to be the perfect backcourt with Mitchell, helping with rebounds on both sides of the court.
3) If we get to keep Rudy to attain him, I can see him throwing a lot of good lobs for easy 2's.
Cons:
1) How does his 30M/year contract doesn't hurt us?
2) Can't close games. Hac-a-Simmons is a thing.
3) Destroys our spacing. If you think our spacing was bad with Rubio, that will be a whole new level.
4) This is probably the most important. Mental Fortitude, we have a team of soft/unconfident players. Rudy is soft, Royce is afraid to shoot, Ingles disapears for key stretches, Bojan can't box out when it matters. Mitchell is the only one that seems ready for the moment. Simmons will not fix it, we might actually be worst on menta fortitude with him.
5) I don't care so much about it, but the guy is too arrogant. That could be a locker room problem.
6) To acquire Simmons we'd either need to get rid of Rudy or Bojan & Clarkson and in both cases that's too much of a gap to address with the remaining assets/cap space.
I see your frustration as all of us are equally frustrated. But looking pros and cons do you still think Simmons is the answer? I say no.
Ball is a better idea. He wouldn't be the best defender, but itens 2 and 3 checks(although he is way shorter than Ben, he is a better passer). It would also mean we would add at least 1 decent perimeter defender.