Items like Toxic Bullets and Silencer incorrectly apply stacks for melee depending on the hero who purchases the item

[BeyondLucky]

Is this meant to be a thing? It seems wrong and melee should apply the same amount for all heroes. For instance, for Silencer Shiv has a 34% application rate so it takes 3 light melee hits to apply it. But for someone like Wraith who has a 8.3% application rate her melee only applies the 8.3% and it takes like 13 hits to fully stack it.