I don't think Joe is going to change the rotation he's had virtually the whole season to accommodate someone else and have him have to learn how to gel with the team with 20 games to go. If anything any addition is going to play a really minor role, some nights he's not going to play at all. So the first question is would Otto be ok with a Blake Griffin type role, where he's going to be on the bench most of the time and might play if Joe wants to give a team a different look.
Also, I don't think just signing someone and plugging him in to an established team that has a lot of chemistry already is as easy as people think, it's not a pickup game where they're freestyling...look at how Tillman is being used right now (as in he's not being used) when people expected he would be getting a lot of minutes and replace Kornet. I think Joe is settled in his top 9 with the starters, Al, PP, Hauser, Kornet and the first deep bench guy will be Brissett or Queta, and his challenge is how does he fit the new guys into that equation and have them playing at their best and in sync with 20 games to go. The rest of them will be just used when the game is in hand or out of hand, or if they want to give a team a different look or they need something specific.
Even if they sign someone who might individually be better than someone like Kornet or Brissett, that person has to make his teammates better, just not be better on his own, and when you're talking about marginal players I just don't see them getting a lot of playing time. I know everyone hates Luke but he knows his role, he knows how to play with the lineups he's put in with, and he's had the whole season to refine that. Same with Queta or even Brissett. Their value is not in their individual skill but in the way they already fit in with the stars of the team.
For a team like ours these players are insurance players. Now if Otto is willing to be a cheerleader and be selfless like Blake was, and is willing to sign for vet min, then sure. But buyout players usually want to play, given he's "ready to play", that's why they're willing to be bought out to begin with. As Roy mentioned if we did sign him it would be with a view to next season, which might not be what he would want. We really don't have any minutes for anyone.