That's only true of the AlcatrazNo , it must be a specific barracks , I rotate mine out weekly for the units I need that week.
They probably let you get away with it because you're a "well paying" player, right?What ever you do don't use FoE Helper and click on production overview and then the helmet up top to instantly show where each troop producing building is at. Don't do this , it is against the rules.