Burning / Poison Mechanics Question

In Siralim 1, if I applied Poison with a High-attack creature and then applied Poison again with a Low-attack creature, the weak (low-damage) Poison would NOT over-write the high-damage poison. (Burn was similar)

I had assumed that things would work the same way in Siralim 2.

Has anyone tested this thoroughly?

I haven’t done sufficient testing to be confident, but initially it seems that High-damage Poison/Burn is in fact over-written by Low-damage Poison/Burn. (That is, it seems in Siralim 2 that I need to be careful not to accidently trigger a second stack of Burn on a target if I already have my highest-damage Burn active on that target.)

I would like to know how they actually works as well. Villainy thrives share the potency of burn and poison but reduces the dmg. What does that actually means?