I don't hate it, but the naming is awkward, needed something more in line with the era, which I am uncertain of. However a mounted commander is far more useful than a foot one. Honestly a bigger complaint is that they switched out the helmet for an imperial Gallic helmet with the transverse crest, that honestly jars more, but again I guess they wanted style points since that is immediately recognizable as a centurion. As to why they might not have gone with super heavy infantry is because Teutonic knights exist already filling that spot. So they went with a stronger version of one of Age II's most notable units the Paladin and tweaked it. To my knowledge Centurions are one of the most iconic units from Age I, so overall likely they were trying to capture that. Did they succeed, maybe, only time will tell.