Giannis has been in the league for 4 years & still has a very shaky jumper which wouldn't be that much of a concern if he had a decent post-up game. He isn't like LeBron who used to the rim at will in a halfcourt set before he had a postup game or jumper. Giannis is more of a transition player & transition baskets are hard to come by in the postseason against elite defenses.
Towns is only 21 but basically has every skill in his tool box, he just needs to refine them & get stronger so he can play center full-time. Unlike AD, he doesn't have health issues.