Kenji’s gazpacho andaluz using canned tomatoes question.

I thought I'd try this after using some store bought tomatoes for a batch of gazpacho (wasn't great). Do you think a 28 oz can of san marzanos would be enough with a cuke, green pepper, smallish red onion, etc.

Trying to start with the right proportions (should I drain the can of tomatoes?)

I am basing this from https://www.youtube.com/watch?v=lD3WyeqCDHw