The Unit.owner of a neutral units is 16, but Debug().DebugCreateUnit() can not create a unit whose owner is 16

I used `Debug()->DebugCreateUnit()` to create units by their information from one instance to a new game instance. But I found there are always fewer units created successfully.
Then I checked them and found no `Neutral` alliance unit was copied. Besides, the unit info shows that the `owner` of the original neutral units is 16. But you know, the highest player id is 15 in SC2Editor -- and the neutral player's id in it is 0.
So I tried to create a unit whose `owner` is 0, then I successed.
But it is still confusing. So I reported this issue here.