If you use the Thrustmaster Warthog Stick and Throttle you could combine them to one device with TARGET. Thats atleast one less controler in the list. Same if you use CH Controlers,they can also be combined within the CH software. Other than that,no idea. You could use something like SVMapper where you can assign key commands to the buttons of the controlers. The keypresses will be recognized by the game even if it doesn't sees the controler.
Or,if you have some selfmade controlers,get a controllerboard that can use 64 inputs. So you can combine 2 of your selfmade buttonboxes (if you use 2 at all...). Thing with this is,many sims only see 32 inputs,so for the other 32 you would have to use keyboard commands,like with SVMapper if it's even possible.
Dann gibt's Heulen und Zähne klammern, für das ganze Lumpenpack.
Dann ist Schluss mit "Tischlein deck' dich", da gibt's "Knüppel aus dem Sack"!