I'll concede that my math is likely silly and wrong, but the overall point is valid, honest!
In the GoT edition, there are further clarifications (can't recall if these are in the original, don't have it with me):
-Pg. 186 under Attack says "If the result beats the target's Defense, it scores a hit and deals damage multiplied by degree of success"
-Pg. 194, "An Example of Warfare", under Step Seven: Orders gives an example of a unit attacking and hitting another unit with 3 degrees of success, dealing a total of 9 damage. As the unit's stats appear earlier in the description, we can see that their damage is 3, making it clear that it indeed damage*degree rather than damage+degree.