Yes you need 156 Strength for Monarch, but you also are likely to wear WTs, Shako, Mara’s for example = +17 Strength. Enigma gives 48 strength when you can first equip it at clvl 65, so you need roughly 91 base strength. But Assassins, Paladins and Barbs don’t need a Monarch, they can get away with much less strength. As Sorc don’t need Enigma, only Druids, Necros and Amazons are likely to invest so high in strength. AP is mainly a BNet thing where you have huge stat bonus from Anni + Torch. In both PvP and PvM the extra vitVitality will help you more than 300 or so defense.