I think event 95 is fine (C2 ensure picking is done by using the compare instance variable). And since you actually wanted the ones that have it to 3, it is not a problem.
However, event 92 would not work well unless gunner1 and highlight were in the same container, which explain that everyone of the highlight actually increase their values.
Since the highlight I think is proper to each instance of the tower, using containers seems logic to do
Unless you are using families, in that case, you would have to link them using instance variables to store and pick by uid