Thoughts on a stamina system with flexible dice pools for combat

I'd like to get people's thoughts on a system I've devised to run combat.

First, the resolution mechanic:

Players roll a pool of d10’s and attempt to obtain one success of the highest possible quality. Higher quality successes eliminate lower ones. Success is graded as follows:

This gives the following breakdown of success rates:

How this applies to combat:

To carry out actions in combat such as attacking, dodging, blocking, moving, and casting spells, players roll Xd10 where X is the number of stamina points they choose to spend.

When combat starts, all characters roll to determine their place within the order of initiative and then act sequentially from highest to lowest. However, instead of all characters taking a predetermined number of actions (eg. one action and one bonus like in 5e) and the turn ending, characters can act as long as they have stamina points to spend. The turn runs from top to bottom of the initiative order cyclically until all participants have expended all their stamina points.

The idea here is for players to make tactical choices. If I have 10 stamina, do I attack twice and spend 4 on each attack to guarantee I'm going to hit while saving 2 for a dodge? Or do I attack 4 times rolling 2d10 per attack and risk missing more, but with the possible upside of hitting more times or getting a Major Success which deals more damage?

Mitigating damage also plays a role in this calculus. Characters can Dodge or Block an incoming attack if they have stamina left to spend on the roll, so a cautious player will always want to leave a couple points in reserve to try to avoid getting hit. If a character depletes all their stamina they won't be able to avoid attacks and will get hit and take damage, and enemies WILL notice if a character is defenseless and focus on them.

Damage is measured with a wound track and the values are baked into the attack roll and scale with the degree of success a character obtains on their roll. For example, a regular sword could deal 2 wounds on a partial success, 3 wounds on a full success, and 4 wounds on a major success. A much heavier weapon, say a two-handed sword might deal 4/5/6 wounds with the corresponding degrees of success. Damage notation is "X/Y/Z W".

Regarding stamina, the idea is that it recharges fully from one turn to the next. However, I am considering introducing a downward spiral mechanic, which is that for every turn after the first, all characters subtract 1 point from their pool due to fatigue. The longer a fight goes on, the more dangerous it will become because characters won't be able to take as many actions, and the actions they take will become progressively less effective.

That's a basic outline of the mechanics, now some of the questions I have:

- I don't know how to reconcile damage, weapon type, and attack speed. For example, as currently written, a dagger would deal 1/2/3W, while a two-handed sword deals 4/5/6W. However, since the stamina cost of the attack is up to the player to decide, there's no reason not to wield the heaviest, highest-damage weapon you can get your hands on. With 10 stamina you can swing 5 times rolling 2d10 with both weapons. Your percentage to hit is identical but the difference in damage is huge. I feel that this stretches credibility and will force players towards certain "builds".

- I've thought about establishing a minimum stamina threshold per swing, so you can swing a dagger with 1 point, but a two-handed sword requires 3 at minimum. However, this feels somewhat inorganic and it doesn't really work because the player wielding a dagger is probably going to want to roll 3d10 most of the time anyway as that's the number of dice that puts you at nearly 80% success rate.

- I've thought about giving weapons properties, like reach, armor penetration, bleed, etc. but unless I overtune these I feel that expected wounds dealt per point of stamina spent is always going to be more important.

- Lastly, I've thought about tweaking the gradation of success on a weapon by weapon basis, so a dagger has an "easy" difficulty scale (1-5 Fail, 6 Partial, 7-9 Full, 10 Major), a longsword has a "medium" difficulty scale (1-6 Fail, 7 Partial, 8-9 Full, 10 Major), while high damage/heavy weapons have a hard difficulty scale (1-7 Fail, 8 Partial, 9 Full, 10 Major). I haven't really mathed this out but intuitively feel like it might work. However it feels very inelegant as it will force players to keep track of different gradations for different rolls. I also feel like this may give too much of a simulationist to players, which I think will detract from the tone and atmosphere I'm trying to create in the game.

Some added context: the system is designed for a high fantasy adventure and dungeon crawler game that is supposed to deliver highly tactical combat that is still fast and streamlined.

Any thoughts you have are welcome. If you see any obvious issues, things I'm overlooking, or just want to share your general impressions I'm interested in hearing them. I want feedback to help me come up with new ideas to work out some of the kinks in the system.

I know there's a lot of missing info too, so if you feel you need additional context on the game and the rest of the system let me know.

Thanks.