have you played 3 tournaments at the same time? I already played that I was a bit lost, I think 2 tournaments at the same time can play with tranquility.
I played 4 tournaments at a time and I do not have a HUD. To make a decision and consider all the factors, I do not have enough time, because often already on other tables will be my move. I feel comfortable playing on 2 tables at the same time.