Using the hit die as a soak damage mechanic in Adventure TTRPG

Two of my goal designs for Lunchtime Dungeons are: simple procedures for shorter sessions and deadly combat. With that in mind, I'm going to test the following hack. I'm open to thoughts and suggestions.

Pathetic aesthetic by Jim Holloway

1. Damage is a fixed number (the max damage of the weapon). A modified 20 on the attack roll doubles it. Monsters (and maybe fighters?) add their HD to that. So a goblin with a club would do 7 damage, and a vampire with a greatsword would do 17.
2. Characters have 2d6 Stamina* and one hit die**, ranging from d8 (fighters) to nothing (wizards). They get to subtract their HD from each blow, and the remaining damage is deducted from their Stamina. 0 Stamina means a roll on the death & dismemberment table.
3. Monsters lose hit points as normal. I'm going to use d10s for hit dice so that some goblins can withstand a blow from a long sword.

 * You can use Constitution in your six-stats game.
** I'll probably rename it to Soak Die or something.

d66 exploration and encounter table for The Lost City

Here's a thing I'm playtesting for Lunchtime Dungeons.
(Click the pic.)

The exploration procedure has been working pretty smoothly for a few months now, but I was inspired by a peek Luka Rejec gave us of his d100 event-slash-encounter table a while ago. Earlier inspiration comes from the Hazard System by Brendan S and some parallel thinking by David Black and Chris McDowall a couple years ago (which had prompted me to work on the same kind of table for Macchiato Monsters).
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(Yeah, I made an HTML joke. I'm not feeling well today, okay?)

So for the next while I'll be dropping the 2d6+1d6 random encounter model and try this thing out. The monsters are from level 1 of B4: The Lost City because that's what I'm running this week. In your game, BOD points can be treated as hits or CON/STR, depending on how easy it is to recover HP.