Tank or fold, is to lose on purpose, so you end 9th or worst on league with the idea to keep the quality and dont lose the 20% avq due promotion.
Mutants are players trained without a proportion in their skills, and until high levels of %... usually about +300%'s but right now as we have no limits between skills as before we have managers training players white attributes till 200% and grey ones are 1% after promote some levels, and those are called semi-mutants.