Oh of course... If all they know is wrestling, then they will lose to a submissions person. I remember reading Gene LeBell's book when he mentioned that he was training an Olympic medalist to enter the UFC (I believe it was Kevin Jackson going against Frank Shamrock). When he started drilling him in submissions, he was told "I don't need that sh*t.." Well, Gene didn't push on it and still ended up working his corner that night.
Jackson lost via armbar out of a double-leg in 16 seconds. After which Gene asked him if he wanted to keep the stopwatch he used to time the fight.
I remember after I began teaching my 2nd nephew a few techniques, he rolled with his buddy (competitive amateur wrestler for 4 years, outweighed him by 35 pounds) and tapped him via an armbar after he took him up on a challenge. Most wrestlers are bait for submissions if they haven't trained to become familiar with the style. Those who have crossed trained, well they're a different story.
It doesn't matter if you agree or disagree
... As long as I don't bore you and I spark a moment of thought, my goal is achieved
Queng leon queng tigre ecu tacacut, queca pa? - Pampangan Mandarigma Motto