I've cooked for a loooooong while (but not a chef) and basically meat seasoning for standard cooking is pretty much the same for meat smoking.
I agree with your hunch that the types of seasonings are pretty much the same and that it just comes down to the amounts. Hell look on any seasoning/rub mix ingredients list and you will see they almost always start with the same 4 seasonings and the ingredients list must be in order from Most used to Least used.
In short you have your big 4 seasonings. Salt, Pepper, Onion, and Garlic (SPOG).
I guarantee that if you just go SPOG on any cut of beef, pork, or poultry that you will be amazed at the flavor from such a simple seasoning! You can even improve SPOG by getting better quality SPOG ingredients (Kosher Salt, fresh cracked or ground Pepper, Onion that is granulated or my favorite dehydrated minced/chopped, and Garlic that is granulated).
Go equal 1 part of POG and add Salt to your preference/needs/liking.
If you make up a blend of the big 4 it is good to do an SPOG all in equal parts and a POG in equal parts where you will add Salt separately because some cuts of meat like ribs can be EASILY over salted when you are trying to get more POG on them.
From SPOG you simply add to get to different flavor profiles.
- SPOG + Chili Powder, Paprika, and Cumin will give you Mexican/Tex-Mex flavor
- SPOG + Cayenne, and Bay Leaf will give you some Cajun flavor (probably a bit of paprika as well)
- SPOG + Ginger and using toasted Sesame Seed Oil will give you Asian flavor (Add sea weed/Nori for Japanese flavor), (Sub Salt for Soy Sauce as well for more Asian flavor)
- SPOG + Paprika will give you pork BBQ flavor
- SPOG + a little bit of Cayenne or other ground Red Pepper gives you a pretty close Montreal Steak seasoning knock off
You get the idea.
Now you can go wild and make a 15 spice mix like some beginners do and I guarantee you that it is basically overkill compared to the simplicity and flavor of SPOG and SPOG+
Once you get good with SPOG/SPOG+ then you can go as wild as you like. I
think the book Dave mentions might go to a whole other level but I imagine we are starting to get into much more nuanced seasonings at that point which again may not fit the bill when Aaron Franklin is making the best brisket in the world with just 2 parts Pepper and 1 part Salt.
(I personally go SPOG on my brisket lol)
So that is my 2 cents and if you are ever a skeptic it is simple to go buy even the cheapest $0.50 seasonings of SPOG and grill or smoke a chicken thigh/quarter with it to try it out :)
I hope this info helps :)