I'm a coach. I feel the only time you should allow your team to score 10 or more is when the other team has 9 or more. As this list attests, that is highly unlikely. I just don't feel there is any reason to score doulbe digits in goals. Teams that do(score 10, 15, or 20+) have likely never had it happen to them. Telling someone you were beaten 7-0 is harsh enough, but 20-1, 19-0....WOW.
This is my opinion.
The other opinion is that if you don't want us to score 10, 15, or 20+ STOP US from scoring. Here again, I doubt these teams have ever had double digits scored on them, and have little idea what its like to be totally defensive, and completely demoralized, for 75-80 min. You learn from playing against better competition, not from getting your brains beat in.