As they are advertised :
MM Tribe : Pay us or we'll kill you
GH : We might raid you if we're bored.
As they are
MM Tribe : We're going to take your money and make up reasons why you broke our treaty
GH : If you're further ahead than us we're going to raid you, or we'll do it for laughs.
Personal Observation
MM Tribe : Bug abuse to find claims, bully new players, kill peaceful players with no warlike trade inclinations, bunch of :palm-heads
GH : Leave people alone 99% of the time, unless they live on the small isle south of melsonia, in which case they raid due to paranoia.