I think there should be T3 armor sets with set bonuses/stats focused on PVE or PVP.
-Let the PVErs farm in Arboreus for their endgame T3 sets that focus on what they enjoy doing (becoming stronger in PVE).
-Let the PVPers farm in Syndesia for their endgame T3 sets that focus on giving you an advantage in PVP. The materials to craft these sets could drop off certain mobs or in certain areas which would make these naturally more contested by PVPers wanting to gain an advantage.