I did my first game as Arabia on Emperor, just messing around getting a feel for mechanics. I'll need to do another game to verify, but even on Emperor, I found the prophets were gobbled up very quickly. On higher difficulties, I imagine Arabia's "The Last Prophet" ability will be a huge swing. True, it sucks that you get last dibs on beliefs. But that one game I played indicates you can get your religion earlier than you'd be able to otherwise (because of huge AI bonuses and their tendency to rush religion), and more importantly, without making any investment in faith. No rushing Stonehenge or scrambling for shrines. Just focus on defense, expansion, and technology, and still get your religion earlier than you'd ever dream of otherwise with zero investment.
I don't know how Arabia stacks up on the whole, but that ability is very likely a 10/10 on high difficulty settings.
I don't know how Arabia stacks up on the whole, but that ability is very likely a 10/10 on high difficulty settings.