The GM seems to be forced with 2 options:
1) Take the most favorable interpretation of tactics.
2) Simply write off the secondary success condition.
The first will make things very long and quite possibly kill multiple players. The second speeds things up and probably avoids PC death.
My table's GM chose option 2 as they were kind. I'm running in a few weeks and will let the players decide by asking them if they want to risk a TPK or not which will determine how I run it.
We had plenty of healing, but simply failed the initiative roll in the last fight. The only PCs to see the boss where the ones that started in front. 4 rounds later, we were simply doing mop up duty as boss was out of LOS on round 1 with trolls blocking the exit before anyone acted.
The GM slipped and told us the tactics, but we didn't try walking into the middle of the lava just to get LOS back assuming it wasn't around the corner before we acted. I do not blame the GM as their actions were perfectly valid based on the tactics a written.
