2 provinces / kingdom is the end of utopia as i knew it. It will turn half the server in super organized 1 tick wave kind-of kingdoms. Whether this is good or bad is debatable, but the gap between haves (11 player kingdoms) and have-nots will push out the have nots faster than any other change can.
My kingdom is discussing it, they're an active core of maybe 8-12 filled with just as many "slackers" that just play out of habit, and eager to "weed out the chaff". This means at the very least 5 people will quit (they don't play utopia because they like the game so much, and thus won't bother randoming, they just like being part of the kingdom)