I think that the 5'10" player is at more of a disadvantage when blocking. Even if you can jump to the same height you have to pull your arms back sooner than a taller player does, timing is tougher for a shorter player.
I don't think that DeBruler for Illinois was much taller than Alaina and she was a beast of an outside hitter. A short player has to do a very good job of timing their jump because a taller player with long arms has a 6" - 10" advantage at the start.
Alaina is also a very quick athlete who can beat the opposing block to a seam and terminate with a shorter set, much like
Xavier does.
Whether she gets tired more quickly should just depend on strength and endurance training. Volleyball is different than bball because of the short breaks in between points. I used to play doubles for two hours and not really get tired.