Knersie I am not clear on your point, did you mean breeders? What do you mean by averaging out?
If you breed a post legged cow to a sickle hocked bull, its very unlikely that you'll end up with a perfect average between the two. In other words don't go to the other extreme to correct a fault.
In this case the original poster had feet problems ( I assume he means he has too many animals with overgrown hooves), he wants to use a bull with a steep foot angle to correct this. My advice to him is to rather use a bull with perfect legs and feet and fix the problem over time than to try and go to the other extreme in hope to get the average between two faults at different ends of the spectrum.
The same applies for all the other traits as well. If you have frame 7 cows and you want frame 5 cows, you'll have more success by using a few consequtive frame 5 bulls than you'll have by using a frame 3 bull and hope to get the average between the 7 and the 3.