Summing ordinal complexity scores (story points) to get velocity is a random...
Summing ordinal complexity scores (story points) to get velocity is a random number generator.
Nothing you didn't already know, I'm just doing fanservice for the likes.
Self-replies
Using an ordinal metric for actual times increases the error bars so fast that the sum is all error.
(i.e. if story points are still ordinal but mapped to hours, then when you do math with them you have to carry the error range and it gets larger for each operation, excluding the magic of LOLN and finding moments of a random sample)
More fan service. I admit, I pander to my audience.