Either it’s an old version of the game, or the dragons were upgraded. The thing is that, for example, a green dragon turns into a bone dragon, but a gold dragon turns into a simple skeleton. :D
As for some people getting “skeletons from dragons,” it was probably like this: they put dragons of one type into a skeleton transformer, and they turned into bone dragons. Then, without taking the bone dragons out of the transformer, they added more dragons – those turned into bone dragons, and the “old” bone dragons, in turn, turned into skeletons, as they should. From the outside, it seems like the “new” dragons turned into ordinary skeletons.
In the game manual, by the way, there’s a direct mistake in this section – it says that “all dragons (level 7 and 8)” turn into bone dragons. In reality, all of them do, except for bone dragons (both upgraded and not upgraded).
All upgraded units look to the left, and non-upgraded ones look to the right.
Except for water elementals...
First, the monster images are different in the hero’s menu (where the doll is drawn), on the map, and in the city (when buying, animated). There are a lot of identical monsters looking in different directions in different images. There are some where upgraded and non-upgraded ones look in the same direction – on identical images.
In general, it’s a beautiful hypothesis, but it’s incorrect.