Seeing as it's already possible to work on getting iLvl 90 gear without iLvl 80 in the mix at all, why is it necessary to wait to have a full set of iLvl 80 before moving on instead of potentially working towards gear from iLvl 70 (CT's iLvl requirement is lower than 70), iLvl 80, and iLvl 90 simultaneously?