This team has all it needs in personnel to win a Championship. Danny and Brad know this, it's just a matter of maturity from and chemistry between players already on the roster that would be the best benefit here. The only type of veteran has even a chance of coming here is one that is great for team chemistry and expects no minutes (think Perkins in Cleveland).
From a logical perspective, Melo will join a team that needs his scoring that can cover up his flaws like the teams involved in the Butler sweepstakes like the Sixers, Pelicans, or Heat. From an emotional perspective, he'll retire after getting thoroughly abused in the media and not wanting to deal with it anymore or joining a team where a friend or respected colleague really wants him to join his team.