I achieved this Team Player trophy (coop/multiplayer trophy) today, and this may be the only possible way with EU account. I tried playing with different players from different regions, never got in to the game because some error. Two controllers on ps4, does not work. Remote play from Vita, does not work.
This is working solution:
You need Vita and PS4. You can use your own account. I used same wifi, on both devices. I have EU region (Slovak one to be specific, but I live in UK).
You must create online game (public match) on PS4, and then on Vita you go to find a match, join your session created on PS4. Pick a stage a trophy will pop (you still need to equip two team charms).