Most Efficient TD Creep Spawner

I have this TD where you can play up to 6 people, and you can arrange teams when the game starts.

2v2v2, 3v3 or FFA.

Now the thing is, I have a trigger for it, but it sometimes forgets to spawn units on some people in the beginning, even though the trigger always look the same and is never changed.

I won't post it since you will just say "this looks fine to me". It is not fine.

The trigger should respond to a unit being sold, and then check each player in the game if he is allied with the one buying the unit. If he is an ally, don't spawn the unit in his TD. Pretty basic stuff, but it somehow malfunctions.

If you were to make a trigger like this, how would you construct it?

And plz don't ask me to post the trigger, I wan't your opinions, not your opinions based on my trigger.
Theoretically, my trigger should work.

Go.

I dont understand your reasoning for not posting the trigger/map. Do you really think yourself incapable of making simple mistakes?

Agreed with CEO. Simple things are generally overlooked. That seems kind of lame to not post your trigger and get help looking for a bug with it. I'd prefer look at your system to find a bug rather than build you a whole new one.

The purpose of this thread is not about correcting my trigger, it's about giving me a view on how other people would handle it, but whatever, here it is: