FAQ contradicts current mechanics? Penance Mark / Phantasms

This is not a thread about whether penance mark phantasms are OP or not. It is also not a discussion how it's supposed to be. There are plenty of threads about this already.

My Problem is one of contradictions in mechanics or at least my understanding about those mechanics.

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How much life does a Phantasm from Penance Mark have? Can you proliferate poisons (e.g. from Master Toxicist) from Phantasms to other monsters?

A Phantasm's maximum life depends on the level of the Penance Marked monster. In a level 83 area, they will have about 20,000 life. It is possible for poisons to be proliferated from Phantasms to the marked target, as long as the Phantasm is close enough for the proliferation.

AND

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How about details of the Warlock's Penance Mark skill?

Whenever the marked enemy is hit, it spawns 3 phantasms, no more than once per second. The phantasms are regular enemies and will fight you while they live, but expire after a few seconds if not already killed. They grant flask charges and vaal souls when slain (but don't drop loot or leave corpses).

I have done a few poison prolif builds quite some time ago and i am quite certain that mobs that do not leave a corpse do not proliferate poison.

Harbinger would be one example. They despawn on death, no corpse. No poison prolif.
On another occasion i tried void sphere to pull more mobs into a boss for prolif. But Mobs that were to close to the void sphere had their corpses sucked in aka destroyed on death and did not proliferate.

Why would this work here? Am i maybe mistaken or are my memories about poison prolif wrong? Was it changed so that it doesn't need the target to leave a corpse at some point?

Please could someone enlighten me? I'm just trying to understand the mechanics here.