See this answer. You have re-defined "set 1" to "mixalpha"; "set 2" is by default "upper case characters". Your pattern can be described as upper-mixed-mixed-mixed. The words you got follow the pattern. What exactly is wrong with them? I don't fully understand your requirements. Please [edit] and clarify. Do you want upper-lower-lower-lower? If so,
-t ,@@@ is enough without -f.