What changes to the staff would help though? Unless Monty plans to try a new defense, what's the point of getting a new defensive minded coach. And if you bring in an offensive minded coach, the team is already pretty good in that area. It'd be great if adding the right assistant could help the players execute better, but the assistants we have now seem to be pretty decent. I just don't see Monty bringing in a new assistant for the purposes of making significant scheme changes, and that seems like the only thing that would make much difference.
Monty has said over and over "We are a help defense team." Now, what he likely means to say is, "Ideally, we are a help defense team, but we are not helping effectively at the moment."
If the coaches that actually spend time one-on-one with players do not get the concepts well enough or can't communicate them well enough, then they need to go.
The guy knows what he wants and know that leaving open 3 point shooters at a high rate is simply unacceptable, but if the guys do not execute well, then something has to change. That could be the demands (so Monty or his expectations), the players, or method of implementation (part of which is the staff).