Here is what you should do:
All pumps under the main canopy need to be photographed and should be evaluated as described. Although the guidelines go further, stating that non-Exxon/Mobil branded diesel pumps under the main canopy need not be evaluated, photograph and evaluate them anyway.
Why? Because the editor's think all diesel pumps under the main canopy are more than likely Exxon/Mobil branded pumps. Let them make that decision.
Next, if there are any gasoline pumps not under the main canopy, you should photograph and evaluate them. Do not bother with other fuel types not under the main canopy - only gasoline types matter. However, as a matter of practice and for my own sanity, I take a quick photo of each one and of their location. Often, the editor will question their location and why they were not evaluated. Also, make sure you note in the comment section on the report that they are not under the main canopy.
Last of all, if you are new and have never done the site, be sure to check everywhere for pumps. Sometimes, there is a kerosene, racing gas, fuel oil pump, etc located at the side or back of the building. I once did not see a kerosene pump because a large box truck had parked in front of it. it was behind the building. I lost the shop because I didn't see it.