I think it would be better if the units that survived the wave were placed according to their starting position in the lane instead of being placed randomly there. A unit that was built in front of another unit shouldn't spawn behind this unit in the middle.
This would remove some RNG that can be quite impactful sometimes and is not related to skill at all because no one has any control on it (afaik).
Example from one of my recent games: an azeria with divine blessing was built in front of a vulcan. Both survived the wave, the vulcan full hp and the azeria with 1% hp. The azeria spawned behind the vulcan to catch the leak, nearly saving the divine blessing because of the randomness of spawns.