OK, not super easy but this way it would save a lot of time for sure.

It could be done by creating a new texture for the Roegadyn meshes, they could have a look of a bulky tiger creature for example.
Ears and a tail could be added.
It would save a LOT of work as all the Roegadyn gear could be reused, some textures would have to be changed a little bit to make the tails fit.
miqo'te headgear can be rescaled to fit the head shape, not too hard because none of the helmets have any sort of animation or physics.

a similar approach could be used for the Roegadyn females...
simply take the Highlander male body...