>>19949384Metagross will be more powerful as a wallbreaker and has better type coverage thanks to it's pretty decently large offensive movepool, as well as access to agility and an (unreliable) boost with Meteor Mash
Scizor has Swords Dance, Defog, and Roost, meaning it could be better as a defensive and support role than Megagross is, the only real utility I could think of for Megagross is screens and you're better off using regular Gross with Light Clay for that