The path specific trait trees are all very deep (as opposed to the general trait trees) and I find that it limits player choice when shaping out your champions to the point that most champions of a given path end up with almost identical traits. I believe dividing the traits into several smaller trait trees would add more interesting choices and incentive to specialize each champion.

The trait trees are laid out in a 5x8 grid so there should be room for several smaller trees with a maximum depth of 4 (with a small dividing line similar to the one used for general traits separating each set of smaller trees).

As an example, I've taken the warrior traits from v0.75 and divided them into 5 smaller trees:

Left side:

{Muscle} - {Expert Bruiser} - {Master Bruiser} - {Decimate}

             \ {Expert Axeman} - {Master Axeman} - {Sweep}

{Discipline} - {Expert Spearman} - {Master Spearman} - {Blade Rush}

                 \ {Expert Swordsman} - {Master Swordsman} - {Parry}

{Dragon Slayer}

Right side:

{Lethal I} - {Lethal II} - {Lethal III} - {Pack Tactics}

               \ {Brute}      \ {Enmity}     \ {Bloodthirsty}

{Reap I} - {Reap II} - {Reap III} - {Uncontrolled Rage}

              \ {Rage}    \ {Reckless}

If any given trait is considered particularly powerful then a level requirement can be added to it for balance (as is already done for some spell and mage traits).