Some of us consider letting several monsters attack you when they cannot hurt you to be unethical at best. It isn't strictly against the rules, I suppose, but really ought not generate any practice. It is the same thing as standing at the magic shop casting rock armor repeatedly in order to train brown way quickly. In any sane progression system futile acts are just wasted effort and garner no rewards.
That is just me though I guess.
Perhaps, Ausuna, if you refrained from bloody attacks with q300 weapons and did not dance around your opponents they might have a better chance to exercise your armor skill but you are likely to find that boring too.
Maybe what is really needed in the current system is a strong multi-appendaged monster that gets 5 or more attacks a round so it has a chance to get one or more in before it dies.
