I don't think so.
Say you have two identical pipes with 1 sq inch area. One pipe carries away one 50 cu inch cylinder worth of gas every second. The gas velocity would be the gas volume per second / pipe area = 50/1 = 50 inches/sec. Say the second pipe carries 2 cylinders wort of gas away in one second or 100 cu inches per second. If these two pipes were merged into a collector, there would be great gas flow turbulance as on pipe is flowing 100% faster than the other.
That is why I tried to make the saimese pipes 2x area of the single pipes - so flow rates would be the same in the collector.
