Also could be a warhammer fantasy/40k situation where magic is kinda unstable and a good chunk of mages are batshit or kinda weak. Sure nobody would complain if Teclis or Malcador offer you healing but neither are insane or weak. Also the reason for that comparison is that I suspect the two are roughly comparible to eachother in their respective settings.
Also the Emperor is the 40k equivelent of Nagash. I will take no questions.