The lane by lane construction is an imbalance in the game simply because all the highest ranked players do only slight variations of the same base all with the L design to maximize the ammount of time spent in the lane by lane time. Proving if it needs to be maximized that it is imbalanced. If it were balanced somewhere in the middle would be optimum or at least average.
So I just worked out my own spell to correct this problem: CONVERT
It converts units in a range around the hero, therefore it could convert a group of units across the lane and be devastating which would add a new danger and help rebalance the game. So I haven’t worked out all the details. Maybe the hero uses the spell and can convert as many units as he has available morale points? These units would be more valuable to him though because these units are spawned where he is or in the next lane way ahead, not all the say back at the tent.