The 320 AMM states one chock per tyre (or one long enough to cover both) for parking in a reaady for flight conditoon - one in front and one behind.
I've known a regulator to ping an operator on this (not A320 but was also specified in that aircraft's AMM).
But tell your friendly safety inspector, unless its written in your FCOM, ensuring the correct number of chocks should be a maintenance procedure! Especially if you're doing the walk around, an engineer has already cleared it for flight, and you didn't leave it there!