If Marquis had not gone down, would the trade have been made? (We'll never know of course). But MD DID go down and we no longer had a backup for PP. And if PP went down, our chances of winning were Zero! Not only Paul's scoring, rebounding, point forward skills, but his guarding of LeBron, Kobe, et al. With JG, at least we have a fighting chance if PP goes down. BUT WAIT (as the TV commercials say), there's more. Suppose KG went down? Again, our chances of winning went to Zero. With JG, again, we have a chance, not perhaps a good one, but a chance.
Danny knew if Perk went down, we still had a good chance to win, with the O'Neills, BB, KG (Yes KG can play a fine 5) and whoever came in a trade for Perk. And Danny knew that if KG or PP went down, we were dead, dead, dead.