How will it be balanced?

I'm an ex-wow pvp player, at an average level. And in wow they always balanced it to be good in 3v3 and not so much at anything else.

So i was wondering, if you choose to try to balance the game in pvp, how you are going to balance it? From wich point of view? 1v1, 2v2, 3v3 or any other PvP system I don't know about?

As the former Wow arena player I am, I would strongly argue that to balance it with 3v3 in mind would be the best option- but that's just my oppinion. What do you guys think? Any oppinions?

In my opinion it depends on a lot of factors.

First of all will mmr or rating in general will ever be brought to pvp in POE ?
Will there be any rewards for pvp ?
etc.

If answer to both of my questions is yes , then i would say balance it around 3v3 like in WoW, on the other hand i think that would be almost impossible cause of so many passive builds / skill builds / item builds .

with this much complexity in a game you have to consider that balancing is really not the point... its how optimal you can make your character build. if one build wins vs everything then you can nerf that build slightly to allow for balance. there is infinite room to make your character better in my opinion