Perhaps but when you tackle someone, you are running at them with your head tucked down, so they are only getting a free shot at the top, back, or maybe the sides of your head. Might still be able to do some damage, but not as likely to get a knockout like that.
I can and have broken someone’s collar bone when they rushed me like that (accidental elbow blow to the collar bone from me covering up). While that stopped the fight and I won from a TKO, I noted that it becomes very difficult to implement ANY kind of hold when your shoulder is broken.