>The aristocratic class surely could eat all the meat they wanted
Aristocratic class with access to wealth and leisure time =/= average ancient person
>Why do people always say this, "most people" are completely irrelevant in this context.
Considering OP asked about "average Athenians", I'd say "most people" is relevant
>This Hercules is definitely at least Klokov's size.
That's fucking HERCULES, you know, a mythological character with powers of great strength? Plus, that's a fucking statue. What you're saying is comparable to future archaeologists unearthing a Hulk comic book and interpreting it to mean people were that big and strong. Klokov is also 6' ft, I doubt most ancient people were anywhere near that tall. Skeletal records suggest an average male height in ancient Greece of just under 5'4" (small sample size, but still). The average height of women in the US is over 5'4".
>big guy
For you
You can definitely get big and strong without weights, but it takes more time and effort and plateaus earlier.
Personally, I worked out seriously without touching a barbell for years starting in my early teens. Pushups, pullups, sprints, sandbags, tires, chopping wood, shoveling dirt, lifting rocks, and manual labor. I got decently fit and pretty lean, and did well when I did track & field and wrestling in high school. I thought I was strong.
That is, until I started lifting weights and had my ego checked. Despite all years of training and athletic experience, my squat, deadlift, and bench press were laughable. After just a few months of weightlifting my strength had progressed more than it had in years.
That said, non-barbell training can do wonders for you. You will get stronger, build endurance, proprioception, and other valuable fitness skills.
Early strongman had tons in the way of weightlifting BTW, even if not necessarily barbells and dumbbells.