Power Herb? It makes 2-turn charge moves go in one turn (like Solarbeam or Skull Bash). It has nothing to do with any of Scizor's moves and it never allows you to go first.
Tri-Attack> Hyper Beam always. Hyper Beam will only KO Blissey if you Nasty Plot, which you obviously can't do because you're Scarfed.
Anyways, this team is a bunch of sweepers with no real defense. You'll never get Scizor to pull off a Baton Pass with all the Skarmorys, Hippowdons, and Swamperts around so you really need to rethink this team and most likely replace most of the Pokemon.
For example, if you like Baton Passing Attack and Speed, you can try Gliscor, since it learns Swords Dance and Rock Polish, but also Taunt to stop Roar/Whirlwind.
Also, welcome to Smogon.