Agreed, in the sense that if Vulcan can drain Stryfe its lights out. Same if Stryfe gets through Vulcan with his telepathy, its lights out for Vulcan.
Though there is a chance Stryfe may be able to fend off Vulcans energy drain, due to his ability to atomically energy/matter. I believe it was implied that Black Bolt was able to do the same, thanks to his own election/matter manipulation.
In the case that Vulcan can not drain Stryfe. And Stryfe can not pull a mind whammy on Vulcan. How do you see this going down?