Was Blaster from "Mad Max Beyond Thunderdome" the same character as the big farmhand from "Mad Max"?

While this sounds like an awesome theory, I'd have to go with "No, they are not."

The farmhand, when Max met him, was an older man, looking well into his early 60s. Judging from Blaster's physique in Thunderdome and given that the third film takes place 15 years after the farmhand scene from the original Mad Max, the farmhand would have been well into his 70s by that point. Regardless of how in shape you are, at that age your skin isn't going to look like a glistening professional wrestler. Especially in a dystopian environment like in the Mad Max films.

I always attributed that look to Blaster's perceived lack of intelligence, yet understanding of "this is how the world works."