I found a caligraphy from the period from an architectural detail, tweaked in photoshop.
TBH they look more from 16th-17th centuries instead of 15th.
just noticed what you were talking about. but there is a second janissary on the bottom left corner with eagle wings attached to his cap and no cavalry there. and the other cavalry doesn't have any shield at all anyway.
obj does not support skeletons, you have to export with the other format.
the textures have infinite padding until they intersect, maybe that's what you refer to?