For the most part, in Europe Marquis is considered a higher title than Count, but it is the other way around in ACKS.
I believe historically this is because domains near the frontier (marche / marca / march) came with greater military responsibility, and hence prestige. I could see the argument for it being the other way around in ACKS because of the benefits afforded to building a domain in a civilised area, as opposed to a borderland or wilderness one, but I still find it a bit strange.
That was my reasoning, yes, but I agree it’s a bit strange!
Could just be an idiosyncrasy of the Auran Empire. Perhaps it’s a case of proximity to the capital or preference for civilised over borderland rulers.
I think one could argue that in order for a domain to be able to expand enough it needs to be on the border in the first place, with baronies and counties inside the civilised area but relatively small, and marches either close to the frontier but with a civilised core, or formerly on the frontier, now big and fully civilised, and retaining the prestige they acquired through war.
Perhaps it would depend on whether civilisation as a whole is on the decline. If it’s doing reasonably well, domains on the border would be in demand from more ambitious and talented individuals. During periods of contraction, it would be the other way around.