Allowing dugtrio in the lower levels just shows hypocrisy at its finest, dugtrio does the same in every tier, trapp and kill something that weakens the other team while you get a non-competitive advantage, if we leave it in UU it will do the same, in NU same. Furthermore, complex prohibitions are the worst, we have enough to have it on movements to have to deal with complex prohibitions on tiers, not to mention that it makes no sense to allow it in UU and NU and not in OU, which is a higher tier.