Bolded what I feel to be the weak point in this statement. The metagame now is really not overcentralised as far as I see. A variety of stall, bulky offence, balance, and even HO are viable, as are many varieties of weatherless, SS, Rain, and to an extent Sun and Hail teams. I don't really see any overcentralisation in individual pokemon either, a lot of options are viable on all the above teamstyles. Sets are the only real way you could say Latios overcnetralises, but given the variety of ways you can revenge it, as well as plan for it via team preview, I don't think this is particularly significant overcentralisation.
What are the many varieties?
I don't mean to sound so "anti-Latios",but aside from scarfers(which tbh, are kinda rare now), there's not much that can come in and kill Latios.
I mean, there are only 3 mons(2 being common, the other being rare) that don't mind using Pursuit in their movepools, which are Tyranitar, Scizor, and Escavalier.
That doesn't seem like a lot.