The standard model is not the be all and end all of physics , so the quarks may not be fundamental. It's therefore not meaningless to say e.g. invented (The quark model is a model that works but it is a model)
Well perhaps but regardless he didn't create quarks. He discovered their existence. No different than discovering the atom - it was there before people discovered it and so were quarks whether or not they're fundamental particles.
Technically he could have invented the theory of quarks I guess.
