I don't understand why people think of Iggy that highly even after last season. Dude didn't manage to slow down any of the players he faced against and Kawhi cooked him easily, dude is basically a bench player that can't get decent minutes anymore. That Curry-Klay-Iggy-Durant-Dray lineup wasn't as effective as it used to be and any effect it had came from playing those 4 amazing players together.
I am not saying Iggy is worse than Melo and not saying he is better neither but from individual stand point without putting Melo into this topic I can clearly say that Iggy is well beyond his time to make any difference in Lakers. Melo would be team chemistry dude that Lebron loves to hang out maybe, that could be the only positive for him and I think his playing would be limited but Iggy doesn't even have that.