Jedi Master Mace Windu Investigation

It appears there is some discordance in the text for Jedi Master Mace Windu and the actual gameplay. 

His leader ability has a clause that reads: "If all allies were Jedi Vanguard at the start of battle, defeated enemies can't be revived, and whenever a Jedi Vanguard ally uses an ability on their turn while no other enemy has a stack of Investigation, target enemy gains a stack of Investigation (max 5) for 2 turns." 

Given that a stack limit is noted here, 5 in this case, it would mostly seem that the interpretation of this should be that when a Jedi Vanguard ally uses an ability on their turn you increase the current number of stacks on the target of that ability by 1 as long as nobody else has investigation. 

As is plays out in game this works if there are no stacks of investigation on the field at all, e.g. you can take a character from "0" stacks to "1" stack. That said it fails to stack moving forward. You cannot progress a investigation stack counter from 1 to 2, 2 to 3, 3 to 4, or 4 to 5 by using abilities which don't have independent investigation increase mechanics. 

If this is the intended behavior the text should be clarified to show it only is intended to add the first stack of investigation. Ideally though the code can be amended to allow for more stacks built up via this ability as frankly JMMW is in desperate need of a buff and this kit fix could at least approximate that without needing a whole rework.