Help with a vgc team

[Marcusube]

Exactly what is Mamoswine trying to outspeed with the 60 EVs?
Run Protect/Quick Guard over Stone Edge. You won't find it easy to get openings to strike down flying types before they KO you so don't even bother. Invest EVs into defensive stats not speed. Scrafty cannot compete with Pokemon in higher speed tiers so it's a waste.

I recommend running Rotom-W as your 6th Pokemon. It cancels out the weaknesses your team has while providing great support.