The only thing I've seen that's odd is sometimes only the unit that started building a T2 structure can complete the structure. It may let other units start assisting but then they will all stop and sit there while the initial builder has to finish the rest. Sometimes my commander will help build it and it will work great until like 90% complete and then he just stops. And by "sometimes" I mean like....1 in 4? It happens often enough to be really annoying.
