Heya! Firstly, thank you for the kind words. I initially did play with parries, as per https://the-last-redoubt.blogspot.com/2021/10/fantastic-medieval-wargame-campaig...
Before an opponent strikes, a full parry can be attempted. This subtracts 4 from the attacker's throw, but the character parrying loses their next blow. If the attacker still makes their roll and gets exactly the number needed, the parrying weapon will be broken by a heavier weapon (or merely dashed away if the weapon is magical) and no damage inflicted. If, on the other hand, their opponent misses the defender is allowed a counter-blow if equipped with a lighter weapon.
It can easily be grafted onto this system (except instead of subtracting 4, subtract 2 as you said) but I chose not to add it in purely due to preference. During playtesting, it was too much to personally keep in mind when doing solo play, and also when I was playing 1 on 1 with a player who was controlling several characters.
I might end up doing a separate version/add-on with extra optional rules to bolt on, such as this, as several people have messaged me saying that they're using this for their group games (with one player playing one character) and I think it would work great for that. Thank you so much for the suggestion!