I agree that the model name is different, 112 slim. It’s not confusing to me and if you look at the first model 112 compared to the current 112s being made you can see subtle differences over time but still very similar.
I also notice that the models 110/112 have other descriptive differences such as pro, lite, slim, auto and so on.
I don’t think that it’s necessary to have a different model number as long as it has a suffix or something added to the number to differentiate the type or style.
I also think the blade shape and design was changed to meet the type of utility it would most likely be used for and general consumer preference. There’s plenty of choices of several models throughout Buck knives and they simply can’t accommodate every individual preference or desire but I think they do a great job of filling most of our needs and try to fill our desires with these offerings the best they can.