[BrianG]

Sometimes, changing coil configurations is just an easy way to get different kv ratings.

You can ideally only have turn counts in multiples of 0.5 (1.5 turns, 2 turns, 2.5 turns, 3 turns, etc). If you use only delta, you are kinda limited in kv selection. Since wye kv is 1.73 times higher than the same number of turns in a delta config, you get more kv selections with the same turn counts.