That plays a part, bot only one IMHO. The suggestion of eye placement, finnage, and mouth size (my addition) would also need to be considered.
We had 2 chagoi we were growing out to learn with. Both stood high in the water as you describe, but one had a better proportioned head, eye placement, mouth size, and finnage. Although they were hatched on the same day, the better conformed one outgrew the other nearly 2-1, while the smaller actually wound up standing higher at the shoulder in the end....