For CDC being DEX based i've seen enough wiffs and unimpressive damage come out of it. I can't say the same for Req.
This explains everything..... you don't actually know how damage is calculated and are just eyeballing everything.

Here's a freebie, Req is more sensitive to accuracy then CDC is, and that's before accounting for CDC's extra acc from Dex. Also CDC is a +15% crit rate @100, you have a 5% base crit rate and +5% from merits for a flat 25% chance at critting @100TP without taking into account gear or dDex. CDC is three this, four with sub, at least one hit will crit per WS on average, more if you get a decent CDC set.

The game runs on a computer, there is absolutely nothing that is truly random.