there is no absoulte mathematical equation between latency and skew, skew may be more and latency can be less, or can be in reverse., one thing i can,, skew can not be more than max latency.
we need less latency because to avoid the effects like OCV,clock jitter, which will be effecting the launch and capture path differently, i dont have any text book or link to prove this, but this is the though i got, am open to discuss on this, and recieve more comments on this