yep you got it. There is no set rules as to what names are used to describe a cut. It just has to say Beef and usually shoulder in the description for an arm roast. So many places try to get fancy with the names so they can sell the same cuts they already have....for example: A Colorado steak is a shoulder blade steak,A Petite steak is used for many different cuts;sirloin sizzle steak, eye of sirloin tip steak, top blade steaks and so on.Its crazy!!
The government was so crazy about making sure we had lables on everything uncooked to remind people to wash their hands after preparing raw meat but, they don't seem to care that some retailers take advantage of uninformed customers to sell a chuck tender steak for on the grill! Not a grilling steak!
Sorry for the rant. hope this answered your question.