Ah well. That means I'll have to actually do work. That's unfortunate
With a reproducible case (i.e. your league), I should be able to figure out what is wrong, and then figure out how hard it is to fix. I'll see when I can get to it.
EDIT: while I'm not positive, I expect I know what is going on. My hunch is that it is a problem of rounding and small numbers. If you take your scoring modifiers and apply them to the displayed average values for each stat, you'll come up with the exact value being displayed i.e. 2.8. My guess is that it is doing this rather than just averaging overall points. Which is silly, but it probably snuck through since not that many people play points-based, and then look at the average stats tab, and then actually pay attention. I'll file a bug and hopefully someone can get to it for you.