i have an idea on how to make this work. there are two side by side lanes and you will automatically target the player closest to you unless you have another player in range and the closest player isn't.
I was going to post saying that I can't see how a tag team would work, but this idea does sound doable.
But there are a few other problems I can see with tag-teaming:
-Finding opponents- It's difficult enough finding opponents at higher levels, and it will be much more difficult finding 3 other players (or another team, if you already have a partner).
-Partner quitting- If your partner quits, you're as good as dead.
-Slowness- Some players have trouble with timer starting late when there's only two players, with four, it will be worse.
So while I think it would be a nice idea in theory, I don't think it will be that popular in practice.