People are too hung up on height. The league is continually moving away from traditional bigs. The Cavs won a title with 6'7 Kevin Love at PF, and sometimes they went with him and lbj as their bigs. GSW won 3 with Draymond Green at PF, and he wasn't even 6'6 without shoes, and they just played the finals with a 6'9 center. Siakam is hardly the most imposing PF, barely bigger than GH, and their true center was an ineffective vet they picked up at the trade deadline.
What we need are good players who fit what Brad and Danny want to do. For now, we have Baynes for those nights we face good big men, but the fact is, there aren't many big men on a night in night out basis who can give you trouble. Lack of height and bigs didn't doom us this year: dysfunction did.
We went to the EC Finals in 2017 & 2018 with less talent than we'll have on the floor next year. No, we probably can't win a title in '20, but IMO, we're one move away from becoming a contender in '21 if Tatum is the player I believe he is.