Units can be a better alternative with mixed types as the A319 usually trims nose up and the A320 usually trims nose down. Pilots have set the correct amount of trim but in the wrong direction.
Using the Fuel Prediction page comes with the caution that you must enter the ZFW C of G correctly on the INIT page. How many times do we enter the correct ZFW because it is available first and forget to enter the C of G after the load sheet has been completed ?
I check both after engine start.