if i remember correctly, there is an event for "unit finishes training a unit"
that would be the triggering unit. the unit that comes out is the trained unit.
When the building finishes training an unit, it will check what building it is and if it a certain type of building, it will create units of the same unit-type of the trained unit.
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.