Here one guy also hints that changing the attributes from armor “could help”: How to NOT get the +acc perk on fighters
But as I wrote there, this 3 level20 thralls I posted above all had FULL STR gear (+10) while leveling up.
I play at Ps4 official PvE server. So everything legit.
And I had either gruel (+14% STR) or the exotic meat (which gives +7 % STR and +7 % VIT) buffs all the time.