ground fighting is definitely something any martial artist should learn but having been doing it for a little bit. i dont think it is wise to take it to the ground in a real life situation and should only be used if it has to be
Tell that to the Gracie family who has been fighting (for real) since the start of Brazilian Jiu Jitsu.... real fights with no rules, BJJ/ Gracie Jiu Jitsu has overcome every style that has challenged it.