Probably. But seems like spell selection changes at some point too. I remember feeling like I HAD to block promised and the hot back in hott and voa or I'd just die. I couldn't prove it (i.e. didn't take the time to), but it felt to me like when I had stuff blocked, they just stopped casting as much in general. Like, instead of casting anything at all, they didn't until they hit the logic trigger to cast the light or word spell. Whereas as soon as I started taking damaged they put something on me. To be honest and clear, I usually 4 box when I'm using a merc, and I'm lazy and run 2 cleric mercs, one reactive and one balanced, which works fantastic for me. But that is due to pure laziness (I can drop a merc for another zerker or a melee merc if I really need dps, but then I need to heal more with the shaman).
