252+ Atk Huge Power Diggersby Wild Charge vs. 252 HP / 252+ Def Skarmory: 146-172 (43.7 - 51.4%) -- 98.4% chance to 2HKO after Stealth Rock
252+ Atk Huge Power Diggersby Earthquake vs. 248 HP / 116 Def Mega Scizor: 144-171 (41.9 - 49.8%) -- 88.3% chance to 2HKO after Stealth Rock
I will give you Ferrothorn, but Ferrothorn is really easy to lure out anyways. Maybe a SCMS edit could put Fire Punch as a mention, but aside from that, I do not see much that needs to be changed. Do not mention Leftovers on Skarmory, Shed Shell is necessary to avoid being trapped by Magnezone.
EDIT: And yes, Magnezone can simply be mentioned as a teammate through a SCMS edit.