Is data usage between networks an issue?

[AC Question]

I have a friend who is currently on the Verizon Network while I'm prepaid on AT&T. He stated that doing the same activities he uses almost twice as much data as I am using. Is this a reported issue? Basically we are both using hotspots for gaming and I want to start using postpaid Verizon because it is cheaper but the additional data usage concerns me.

 

[ManiacJoe]

I would first question how the data usage is being measured.
Then I would question "doing the same activities".