There are many who believe that. The manufacturer and number is enough. I believed on a military gun, a part was a part. When I found out the manufacturers of the parts, that changed everything. I found I could not hold, and shoot an Inland carbine with an Underwood slide, Rock-Ola trigger housing and Winchester bolt and SA stock.
I had to make it all Inland. I did not care what type a part was just as long as it was Inland. I just believed a Winchester part belongs on a Winchester carbine and so on. From there you have started on that long slide down to the dark side. Them I picked up a FM that had the revised parts listed as "Do Not Use". All of ya'll have seen those. So I took every old part out of my carbines and put all the latest type parts in. I went to a gun show parts dealer and traded all my "Do Not Use" parts one for one for the latest part. Boy was I happy to have gotten rid of that old junk. Type 1 and 2 and 3 push safeties, and type 1 and 2 mag catches, you know, junk like that.
Now, I have bought many carbines because of just one part. I don't do much swapping of parts now and I have been selling excess parts.