i doubt hamlet battles will be super tough and as long as ppl aren't stupid you just invite someone who's around and do it. and when they add the other 2 hamlets i just assume times will alternate so you could always battle at one of them.
what's not so clear is what the rewards will be: in the example is this just a rating, is actually exp or even GC seals? i just hope this will offer a good payout in seals.