It's all bogus in my opinion. [...] it's soo random and all over the place.
There is a large amount of randomness in rewards, but CB$ reward is always picked as fixed fractions of the average net rewards.
I don't recall from memory what the fraction are for sure, but it was something along the lines of 7/9, 8/9, 9/9=1, 10/9 and 11/9 of the average. I'm fairly sure it's not THOSE, but something similar.
Average XP reward is always a constant multiplied by average CB$ reward, but the actual values XP can take are far more numerous.
You will notice almost exactly the same numbers repeating a lot for CB$ rewards, with actual possible rewards clustered in only a few groups (variations mainly due to own VPR and opponent score changes altering average net reward very slightly), so in a few fights you can gauge what the actual average CB$ reward is if you keep track, and the average XP reward is proportional to that.