I'd add him over Varlamov. I'm an Oiler fan and have seen all their games so far this year. Dubnyk has been the real deal and has looked awesome outside of 1 bad period against the Sharks. He's playing well positionally and controlling rebounds. Now that he has established some solid play he's going to get most of the starts going forward because the Oilers are still building and Khabibulin is hurt and terrible. The team is starting to play better D in front of him, still not great, and now that the young guys are rolling and putting up more goals on the other end he'll get more wins.
I'd definetely add him over Varlamov. Since your league includes SV and SA I would prefer to keep Ward whose real value is in those stat categories. Swap Varlamov for Dubnyk.