A is sneaky, manipulative, deceptive.  I hate these qualities more than I hate out and out defiance.  With her underhanded way of doing everything, I have to guess and it gets tiresome. M is easier to deal with.  At least she is honest about hating me or not wanting to do something.  Defiant, angry, explosive - yes - but I think that is easier to handle because at least I know what I am up against.