Of course everyone would like to have better models for each unit. The problem I would see with a change is that especially every additional polygon consumes more RAM, whose volume is limited to 2 RAM by the game itself.
Especially greater numbers of horses are usually jumping over the map; compared to a single troll for example.
I do not know the mod which uses the models exactly, but the Edain Mod is already very extensive in the model and skin section and also struggles with performance problems.
I therefore suppose that you could implent the model or something compareable but it would disturb the performance. Just my humble opinion by the way
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