Correct me if I am wrong but if you are gearing for the chance that the crit is forced, wouldn't crit dmg be equal to WS damage anyway?
I think it would be smarter to just stick with straight WSD in all slots so you gain the benefit even in the occurrences of non-crits.
If it doesn't force it to be 100%, Crit Rate should beat both cdmg and wsdmg I would think. For instance, if it's like 20% crit at 1k tp, I would think crate would win out.
That's how most crit hit WSs are geared at least. Crit rate for consistency, then crit damage next. Most don't require wsd simply because most of them (evis, drakesbane, vorpal blade, etc) are multi-hit - but I would assume wsd would come after crit rate/damage.