Minecraft 1.19.2
Fabric 0.14.19
Fabric API 0.76.0
MidnightLib Fabric 1.0.0
Guard Villagers 1.1.2

Testing: Armorers are not fixing guard armor even where they would fix golems. Configuration file is set correctly.

Never mind I'm wrong lol

Armorer fixed the enchanted diamond chestplate that I accidentally spawned in with negative durability, up to about 266/528 durability (yellow). Further testing....

Diamond leggings to 249/495 (yellow)
Diamond boots to 217/429 (yellow)
iron boots to 100/195 (yellow) (very slow)

Save and restarting the game...

The durability 1 enchanted gold boots were repaired to ~48/91 (yellow) even when the golem is no longer being repaired.

So they do repair, but it has to be armorer and it only repairs to about 2/3s