I don’t mind answering questions I love talking about all this stuff! Just mentioning the situation in case there’s a long delay in replying (like if my phone service loses internet too) and to apologize in advance for typos and weird conversions that my phone does changing words when I’m trying to use voice to text.
If you’re having long, inconclusive fights then something’s wrong.
Armor can skew the lethality a little bit, but the key to the system is really stacking up your dice. In other words, instead of waiting for a critical you kind of force it to happen. You do this through gaining Free Dice from Martial Feats and circumstances in the rules.
For example using Martial Feats like Meisterhau in attack or Distance Fighting in defense (better yet with a buckler). Always using an aiming support like a wall or a tree limb every time you shoot your crossbow or your arquebus gives you a Free Dice. Many of the Martial Feats combine together. A 6th or 7th level character can be very lethal if they leverage their capabilities. Combat in a lot of RPG systems is set up to interfere with min-maxing, but codex actively encourages it. Harness that instinct to apply the system as well as you can, customize your fighting strategy to your character, and that’s how your PC becomes powerful rather than just having 300 hit points or a Power Word Kill spell.
That said, really good armor can still be very protective. It becomes necessary to use special armor piercing weapons and rely on grappling. It’s also recommended to use the hit point ceiling 2X or 3X the Constitution is good threshold. Also take advantage of the rules like twist The Blade, Artful Strike, Charge etc.
When you’re introducing new players to the system which of course can be a challenge since it’s quite different, I have two recommendations. First start simple- you don’t have to apply every single rule at first. Get them used to how the Martial Pool works. You can layer in new rules as they run into problems that sort of beg for them if you get my drift.
Second do a “session zero” and let them fight a few opponents that aren’t too tough. That should give them a taste for it. I have run games with Hema people who kind of naturally grasped the ideas, and I’ve run them with hardcore gamers that were not used to anything like this and have probably never been in a fight in their life. I found it wasn’t too hard to get people into the system. Obviously it helps a lot if you know it beforehand. Doing little solo battles is a good way to figure it out.