Modifying mounts in the EDU, does it affect stats?

[Chinaski]

Hi there,
I'd like to give my Ayyubid Royal Guards some Eastern armored horses via the "mount" line in the EDU, but without modifying their power. Does the mount type affect the unit power in any significant way or is it only the texture?

Thanks!

Edit: Well I just read that the horse's mass make a difference in the charge lethality, which is a problem. So, what if I just use Abbassids bodyguards stats for my Ayyubids guards ? Are these two units significantly different, would the Abbassids guards give an unforeseen advantage to an Ayyubid army?