the problem is not that pyros are too cheap, or to strong, the problem is venoms low health.
If your units bunch up - much likely in every fac except vehicles, the pyros are strong.
Pyros got 3 times as much HP as a glaive, 2 pyros + 1 puppie:
* Venom stunns puppie (ground is closer than pyros with y-distance)
* 2 pyros jump to venom and kill it (maybe get hit twice)
* something about 3 seconds stunned, but can savely retreat.
* recluse wasted it's shots against puppies and can't kill pyros as fast as needed.
Venom+recluse is about the same metal as puppie+2pyros, but venom get killed.
Riots are slower, so pyro is allways the attacker (microed) while the venom player has to react at time.
Hell - 2 pyros can kill 1 warrior or 1 outlaw and retreat with jump.
They are riots by their own, but are called raider.
There would be no problem if they get buffed, but nerfed in velocity.