You don't need to duplicate it. You just need to find something that works for you.
I am not a BRITU fan but give it a shot and see what you think.
Here is one you might try. (The recipe calls for some paprika. Actually I used aji amarillo but, being new to the board when I posted the recipe, and not seeing much at the time, here, that included much in the way of non-standard chilies, I switched it to paprika for posting.)
Here is another I wrote for a member. Were I making it for myself I would cut the sugar to 1/4 c and likely use white or a 50-50 blend of white and light brown.
I almost never use sugar in beef rubs unless it is needed to balance acidic an d sharp ingredients (like
this one for brisket, inwhich I used dark brown sugat to soften the coffee and cocoa), never for most poultry, but I do like it in most rubs for Q'd pork. Again, to me, excessive sugar deadens flavors by dampening the higher flavor notes (think of the difference between lightly sweetened ice tea and heavily sweetened -- or too sweet lemonade -- the high notes are lost). However, if you make a rub that seems to work for you in most areas but isn't quite right, first try remaking it with less sugar and see how that goes.