Bronica at one point was selling
40mm,50mm,60mm,75mm,105mm,135mm,150mm,180mm and 200mm. That's no more then 30mm between lenses. Many closer then that. They have some differences. Off the top of my head the 150mm focuses closer then the 135mm or the 180mm and is a touch faster. But not anything major. You got to choose your favorite focal length.
Later they yanked the 105mm and replaced it with a 100mm macro lens. I'm not sure I understand this one since it doesn't focus very close. Maybe I'm missing something.