I don’t know. Some of them trained teams to draw them, but I don’t think anyone could have duplicated Peanuts. :)
Back in the late 80’s or early 90’s, an ancient little old man asked me for directions. I traced his route on a piece of paper I had in my car and gave it to him. He asked for another sheet of paper, then drew a drawing of Moon Mullins, wrote “thanks,” and signed it, Ferd Johnson. I was aware of the cartoon, but didn’t find out until later he took over after the original artist died. It is still cool. I framed it and it still hangs in our TV room.
Heck I still Miss Henry Snuffy Smith and Sluggo
But the best Comic ever done EVER is Calvin and Hobbes.
Why Watterson retired is beyond me
The Peanuts drawings all became jagged when Charles Schultz’s health declined and tremors set in. It was a sad thing to see happening, but I’m glad he stuck with it as long as could.