Think of your pending vote balance as a container full of water. Your voting units determine the rate at which water flows into the tub. Your posting behavior determines the rate at which value flows out of the tub (into votes).
While all units fill the container at the same rate per unit, the rate at which people empty the container (by posting) can be very different.
To accurately compare yourself against somebody else, you would have to correlate total units against all pending value plus all votes already delivered, over the same holding time interval.
This is explained in detail in our documentation:
https://docs.hivesbi.com/fundamentals/pending-balances-and-upvote-delivery