As the title suggests, it would be cool for each UU to have a downgraded/upgraded version of the current model
that represents it’s normal/elite variant.
The drawbacks of this are the amount of work required (More than 35 new models required), and it will probably confuse some players at first.
At least we already have the Royal Janissary (it could be used to represent the Elite Janissary)
(I know that this screenshot is from old AoE2, but it exists in AoE2 DE as well).