To say that the Greeks didn't have correct scientific theories is obviously true. To say that they had a methodology that departs from ours is somewhat true. To say that they were merely making stuff up without reference to any observation is to merely make stuff up without reference to any observation.

I could do someone significant bodily harm by hitting them with Aristotle's collected empirical works on the anatomies, reproductive systems, social habits, and forms of locomotion of animals. And I'm not a huge dude.