Part 1-2 are nothing like Hokoto no Ken beyond art Style, Fist of the North Star has always been about Kenshiro being a broken piece of shit and beating up weak people who take advantage of others, while jojo part 1 & 2 are about incredibly weak characters finding creative ways to take down opponents who are much stronger.
The art style is incredibly similar, but even then, Fist of the North Star started out as pretty "bad guy of the week"
Part 1 & 2 are definately shonen as fuck, but there's a level of self awareness that araki has with those parts and a level of creativity in his work that makes it really shine in comparison to other manga that basically looked like Fist of the North Star.
Also, Fist of the North Star would be an awesome group watch with you guys. I think it gets a lot of unfounded hate for no reason, but it really shines in a lot of places, has some good ass character scenes, and really makes you want to shed manly tears.