Hey,
I want to share the following house rules, to get your impressions and suggestions.
After having played many time to Pendragon RPG, in our group we found the base damage that PC's make tends to be nearly identical (5d6 nearly always). I know that different weapons and other circumstances make them vary, but what about using this little house rule just to add more fun: I thought about including an extra bonus (sth small: +1 and +2) for stronger characters.
E.g.:
STR+SIZ Base damage
...
21-22 5d6
23-24 5d6+1
25-26 5d6+2
27-28 6d6
29-30 6d6+1
31-32 6d6+2
...

You are out by 1d6.
21=4d6
27=5d6.

other than that, your tweak doesn't seem too bad.

Yeah, you're right, it's a mistake.