Sunnybeam isn't a reliable combo. Sceptile would have died before he has a chance to pull Solarbeam off.
As for Facade, why not just use Regular Poison instead of Toxic Poison? With Toxic Poison Salamence won't last more than 5 turns. Normal Poison would keep him alive at least 10 turns.
Is this Salamence supposed to be mixed? Dragon Claw is special in RSE.
As for Headbutt I'm not sure what to say...but there are better moves out there.
This strategy is mediocre at best, so 4/10.
And, like this.