^exactly what Dusk just said.
The easiest thing I see that could be done to this team to deal with Tomohawk is just to replace something with a Krilowatt. Vaporeon is the msot obvious for being a Water-type, but obviously wish support is hard to give up. I think I would recommend replacing either Necturna or Kitsunoh though, since having two trick-scarfing Ghosts is a bit excessive. Krillowatt also tends to lure in things perfect for Togekiss or Heatran, so I don't think you lose much synergy.