Stats from statisticians of respective teams are more reliable than stats via FIVB, and stats provided by Bogdan are from a Serbian NT, so conducted by a professional statistician, not to mention that they're much more complex.
Complex is not necessarily a good thing, seeing as we ourselves are not statisticians. And I would dispute that the stats from each teams are inherently superior to FIVB ones. You could have a shitty statistics department that isn't motivated to do its job properly with low pay, and let's just say I wouldn't be shocked if that's the case with Serbian NT.