Pigeons are a tool just like a shock collar, whoa stick, or steady barrel.
Too Much is never a good thing
The reason trainers use pigeons is because they are inexpensive and fly several times with a teather on it. Also they return to a cope when you launch them.
They however, are no subsitute for finding a wild or realesed bird.
If your dog ever points a pigeon in the wild chances are he will get run over under the bridge.