In rain scald would still overpower hp electric vs skarmory, and out of rain surf would too, so I don't think that's a problem^^ Obviously you aren't going to be running two water moves on one set, but I think just running ice beam for dragons in the last slot would be best really :)
If you agree with me, would it be okay if I went for hex flawless? because that spread is really easy for me to hit (since I've done it a bunch already)