I don't see why not. Hell, throw Q in there to sweetin the pot up. I always said Helm would automatically become their best defensive forward plus he'd be an upgrade at the center position behind Hopkins. K, Q and Helm for Petry and a 2nd round pick.
I get that trading Helm allows us to bring up Pulks and that trading Q allows us to keep XO up, but I think that's a tad bit of an overpayment. Although that 2nd round pick would be quite nice the way EDM is trending.