It looks like birds aren't the problem, because (Wrap) Tentacruel is proving to be oppressive due to Wrap combined with 100 base speed.
We can test a bit more (teams including Haunter and fast pokemon), but I think it will eventually need to be banhammer'd.
At first glance SD Tentacruel looks viable and still fair in that case - you know what I mean.
EDIT: it starts to look better, but you really need to pay attention to teambuilding and I think losses due to unanswered threats are going to happen anyway.
I'm currently using Dugtrio/Hypno/Kadabra/Kangaskhan/Tentacruel/Raichu, which gives you an idea of how much speed is needed.