This is apparently being discussed,
Lastly, and for transparency, we wanted to let you know that we have been experimenting with some foundational adjustments to Deep Wounds and Ignite to fix the very authentic–but very frustrating–“Munching” effect that causes these spells to not stack properly when two attacks that add to their magnitude land at the exact same time.
From this which which won’t link properly , [WotLK] Stealth change to Feral - #4 by Basîl-benediction