My experience with my Kirby amiibo, which is the only one I ever intend on using, is that it mimics my inputs at a given rate based on its level and the frequency it's seen it, regardless of what character I was using. So if I do fast-fall fair to grab repeatedly as Pikachu against the Kirby amiibo, Kirby will attempt to do this input even though it's pretty fruitless for Kirby almost all the time to go for a grab like that. That being said, you can train your Amiibo to input certain inputs more often than others, but not exactly when it should be inputted, basically the AI is pre-programmed at max level to read 'optimal range of use' and regardless of whether or not it's actually a feasible option, it just says go or don't for whatever it is. I thought this was fairly obvious, but I dunno. That being said, you can teach Luigi to dthrow fair, or Diddy to hoo-hah kinda sorta because if you do it a lot to them, they're going to up the frequency of those moves too.