Louis,

To use battle results to answer this I think you would have to play against a defender who is your equal in skill, has exactly the same army as yours and knows enough to conserve movement. I think both the shooting and fatigue disadvantages can be reduced to the point where they don't determine the outcome, but you have to be aware of them or else you won't take the necessary steps to minimize the effects. Minimizing the effects is going to limit to some extent the tactics you can successfully employ. Starting a melee one bar down in fatigue isn't good, and I think it's suicide two bars down provided there isn't some compensating factor such as lots of flank hits or a big outnumbered penalty. We know that the fatigue rate was optimized by CA for the smallest map size, but 4v4's are often played on the largest map size where there is a lot more walking involved so it's more of an issue there.