Please feel free to correct me if I'm wrong on any of this. I've just started playing again so I'm not sure of all the updates

The OL blocks as a unit and the DL works together as a unit. That being said if you have a three man front (3-4 or dime) does the average of the three compete against the average of the five man line? If that is the case would it not be smarter to use a 3 man front so you still have 8 men going against the offenses 6? Am I missing something here?

I think it would depend on how you have your linebacker assignments set up. If you assign 2 of your linebackers to the line, then you would have a total of 5 on the line, and 6 in the backfield - matching 1 to 1 with the offense.

And I don't know if it's really an average of the linemen's ratings, or a total of the linemen's ratings.

See I've always believed that it was an average. If it's a total then my 3 DL would never be able to get a sack on your 5 ol but that kind of thing happens.

i believe it is an average, but that there is a modifer that depends on the number or players each side has set to line or block.

The OL works as a unit, but the DL works as individuals.

http://www.whatifsports.com/forums/Posts.aspx?TopicID=465022&TopicsTimeframe=30

Read this post. If you figure it all out, please share with me