it is true that if you are more skilled in BJJ you will be able to put your opponent in a hold faster in most cases....but you are still in a compromising position, especially if he has "friends" around.
also, short of choking him till he his unconciouss or breaking a limb...it is hard to get an opponent to submit...."tapping out" doesnt end a streetfight.....at least if you knock him out, or knock the wind out of him, or break his nose he is unable/unwilling to continue fighting.