A Little Confused About Dex per w.atk and how it differs from STR-less to low STR

how much dex is equal to 1 atk, at current state:
dex/atk = (3.6*dex+str)/(3.6*atk)

This formula is only true for your maximum range, which isn't nearly as important as your average range. It doesn't account for the fact that DEX does more for your maximum range than your minimum, while STR gives the same amount of damage to both. Though this is extremely close.

After some testing I've found that Dusk is definitely right: there's no way a 100 Neschere can beat a 120 Normal speed crossbow. In the end low-str will always triumph.

For most people the dex to attack ratio seems to hover between 5 and 6. It's usually closer to 6 if you're less funded (dex cape, dex shoes, etc), and closer to 5 if you're more funded.