It's not like they have to learn all the models at once, CDJR; Chrysler, Dodge, Jeep, & RAM only have about 25 models between them, Stellantis added lines but those were the core vehicles new car dealerships sell. Yes, I've learned a lot about the Chargers and Challengers in the last nine months and have more knowledge about the differences between the trim packages than most sales people, then again I'm not being paid to know what they are.
The sales guys don't seem to care whether they work at the Gap, Zales, or a dealership. When one can't tell you the difference between a Charger and a Challenger it leaves me with the feeling they don't know what they are doing and I can't trust them to present me with reliable information. I get where you are coming from; 'I just dropped out of my Freshman year at Generic State and have no experience outside of flipping burgers dads friend's car dealership hires me as a sales guy and I've never owned a car, just started last month' or some mega used car lot with three dozen different manufacturers represented (remember Saturn or Datsun*?). I don't expect a grocery store clerk to know much about any product, I expect people who sell specific products to have more than passing knowledge of them.
* Datsun brand was phased out by Nissan but returned 10 years ago, I don't think they are in US market.