I only see Marauders being used as the 4pc, but looking at the 6 pc vs Nats, it sounds like the Marauders is stronger, with more ramp up time, and sentry management.
Marauders 6pc Math:
3000% damage per Sentry max 5 sentries is 15,000%
Nats 6pc :
plus 60% Damage reduction.
So at base, Marauders destroys Nats in damage, but Nat's toughness huge, is that the selling point?
But am I reading that right or is Nats damage more comparable than I think?