1. Small sample sizes and whatnot, as
@RedBlackAttack and
@jking948 have already discussed.
2. For a 19-year-old player, the trend is super important. Let's see how your stats hold up over the past 10-15 games, now that Garland has better conditioning, is showing more of his quicks, and is generally figuring out the game more.
3. The point of this season is not, and never has been, victories. If anything, we want to keep the lid on wins, so that the draft pick doesn't go to New Orleans. If the Cavs played Delly over Garland, and if that change resulted in more wins (hardly a given; see points 1 and 2 above) ... that would be all kinds of bad. Fast-forward six months. Your approach leads to the Cavs having an under-developed Garland and no draft pick to join him. The Cavs' approach leads to a much more developed and confident Garland being joined by one of the top talents in the draft.