Here's my take on this:
(1) Some players in the league get away with this, but it is a small group.
(2) Danny Ainge knows this, and knows that you need one or more of "these players" on your team to consistently win.
(3) Compile a list of these players. These are Danny Ainge's ultimate targets to create a "New, New Big Three" (though there may be intermediate moves).
I know my points 1-3 above might seem a bit off topic, but they're not. The point is: this is how the league works. I hate it, but that's how it is. Given that these are the "rules of the game", which players can we get that help us win, given these rules?