I've haven't seen resumes, passports or birth-certificates to compare anecdotes, but I've been to master tailors and I've been to Moore's - all take more than three measurements even to just pick from what is pre made. I have a friend who has researched this and concluded five measurements would be the minimum to ensure fit of both pants and jacket ... A quick google search seems to corroborate this with the hits demanding either 5 to 6 measurements or 15 to 20+ measurements. From my own very limited exposure to anthropometric design (engineering things so they will fit and be usable by people), I know that waist is not an invariable predictor of chest, and that neither height, inseam, nor sleeve length invariably predicts one of the others.
I'm not suggesting your old Italian is the only guy who knows his trade. Maybe you exist on the centre of every bell-curve of human proportions - you fit all the assumptions a tailor would make given less information. If your guy is as good as you believe, he could probably see this (much as you can look at a crest line and see the number of fighting vehicles to fit into it). He only took three measurements because that is enough for you.