Interesting dilemma indeed... but for now most of them are relatively far off.
Legitimate tankers: Sac, Pho, Orl, Lakers, Atl
Bad Teams: Nets
I don't see NY trading Porzingis. Hitting on a unicorn is rare. He's a contributor in his second year.
Memphis, Dallas, N.O. still have enough talent to make the playoffs... so they're not a tanking threat.
A Butler trade will return an All-Star or significant picks. If he's going to Cavs it'll be Love.
I think Indy keeps PG, for his last season if offers don't get significantly better. It's better to put a viable product out there to put fans in the seats and let him walk for nothing. Than trade him to Lakers for Randle and late first round picks... which is essentially nothing as well. That being said, any trade made for Butler could also be made for PG.