When you factor in one is getting over 120mln for 5 years at the end of which contract he'd be 35 year old, and the other is getting 63 for 4 years at the end of which he'd be 28, I think it's much harder decisions than some might think. Declining/aging Carmelo vs rising/prime Hayward for half the price... I am leaning towards keeping Hayward... There were some interesting advanced stats that show that he's nowhere near deserving max contracts and even his synergy offensive efficiency is ranked 20th in the league:
https://www.youtube.com/watch?v=ASoQqibX0TY