While Doc did sport a ripped shirt or even shirtless in the original pulp covers, it wasn't always the case.
|One of the ripped shirts on a cover|
I guess that while the ripped shirt look, may look like a man of action, I sort of like the classic, 30s look of the suit and tie. He might end up with a ripped shirt by the end of the adventure, but I don't think Doc started the ripped clothing trend.
Of course anything is better than the Marvel comics vest that Doc wore