I learned a few important things actually

good guide.
One thing I tested tho was that soft ac is worth much much less than hard ac. I couldn't figure out how the exact calculation works so I just went by comparing ac values for steel plate vs mammoth guard and dragon helm vs troll helm.
the only time the full value of your soft ac is taken would be when you get a big cleave and the damage goes above a certain number. but mostly with medium or low cleaves soft ac is way less effective.
for example same quality dragon helm should be sligthly better than a troll helm
and iirc q200ish steel chest should be better than q280 mammoth guard (I think this test had similiar total ac values).
I can look up exactly what and how I tested if you want to but hard ac >>>> soft ac was the outcome
edit: I think I can only say that hard ac is way more important than soft ac in general but you shouldn't quote me on exact numbers since idk how accurate my tests were anymore xd