Your path doesn't matter in this matchup.

Man. First of all you're not paying respect to just how much level difference matters in a caster vs priest matchup. If you have 3 levels on a muter he's not perma neuroing you. He's just not. And if by some grace of the RNG gods he is, he doesn't have the mana to sustain the lag. Especially not at 37. Neuro is a high mana cost spell. You have protections he can't dispel + dwarf hp.

But all your shit is landing. -15svs means he's maybe getting 2 lagging neuros on you. And you could get to -25 svp as a dwarf shaman really easily. Plus your svs should be pretty high.

You have a few fight to kill him options. One is to go for the damn/curse rope a dope. Make him think he is winning and run him out of moves/mana. I'd open with damn or curse then look at plague/blind/famish.

I'd make sure to illuminate so he can't hide via duo. Then just stick on him. I wouldn't go for energy drain until late in the fight because most casters panic when they see energy drains start coming out.

Also staffs are typically heavy and the only +str he has is likely giant strength and MAYBE enlarge (doubtful). He's a low con race which means he's easy to plague(which stacks -str) and you have levels on him. 2-3 plagues and he drops that staff and then you're getting two free melee hits a round.

This just isn't a fight a good shaman is losing.