The whole "Top Tier" thing comes from the AR-15 world where it defines if all of the Mil-Spec requirements are met. Colt, BCM, Noveske, Daniel Defense all meet the Mil-Spec and TDP, and are therefore considered "Top Tier". It filters down from there as to how much of the gun is Mil-Spec, and how much isn't. Some companies batch test MPI and HPT for bolt carrier groups, while other "Top Tier" builders check every one. Others like Olympic Arms don't do much of any of it. Their guns still run fine, but would never be considered by the military, anymore than they would consider a $9.95 toilet seat from Home Depot when they could get one for $10,000.00 by having contractors submit bids.
Now when you get into handguns all of this goes totally out the window because there is no Mil-Spec to be met, except for the Beretta M-9 Service Pistol. Many handguns cover that easily. From there it's all apples and oranges. In short, I don't think you can apply it because it all falls into personal choice, not a dictated specification.
For example someone might consider Weatherby a "Top Tier" builder because they like the high luster finish on a Mark V DeLuxe. Others think it's too pimped out, and prefer a matte "Tactical" finish, and so on. A Kel-Tec might wind up running better than a Springfield XD, or it might not. Which is "better"? It's almost impossible to ascertain.