Styles = art. If you cannot use something from one or another style, that is of use then the problem is a fixed attitude.

I still say (within weight range) the individual real street fighter (hard core muther fucker) will adapt and beat most martial artists of only one discipline, whatever it is ,from whatever country.

Theres a couple of exceptions out there but generally speaking going on the regular people that fill in all the halls and gyms that go for self defense or fitness or the arts sake or the spiritual side of it they havent a hope against a natural killer.

Also most martial arts are stages that go from fists to swords to open hand teqniques where the eyes are the main targets in the final form.

MMA is the real modern day answer for cage fighting though, Kung fu has no business in there.
But some techniques from some of parts of them most certainly can have a place in some circumstances.

Talking about philosophy of fighting: the worse thing anyone can carry into training or the ring is their ego built from a fixed attitude.