Ravenous Swarm Poison Stacking

My max for my other abilities are 10 via;
building toxins(passive)
stacking poison(passive)
overwhelming toxicity(pathfinder passive),
snakebites(unique gloves)
escalating toxins(support gem)

I am able to get 2 poisons stacks off of ravenous swarm(ravenous swarm + escalating poison)

Let me know if this operating correctly or if its bugged.