Hello. As a fan of AOM I want to make this retold the best possible, so after playing for few weeks now I will try to give some feedbacks :
Like the title said, it would be very cool to have one regent model per civilisation for the regicide mod. It’s a cool model that can be use/re-used for custom maps/campaigns for the players aswell !
Since they made it with the citadel unique model per civilisation, why not for the regent/king unit ? 
For the egyptians it’s a bit weird since they have already the pharoh, but technically they could make a ‘‘higher tier’’ pharoh to represent maybe the kings of kings. And technically… you have already many pharohs in the same game if people choose egyptian so… probably not a problem.