My Gs have FS and drop back very quick on some plays. They only seem to make an extreme drop when they actually have a blitzer to pick up on the other side. When there is nobody to block they just kind of bounce around. Below are two quick examples of what I am talking about.
http://goallineblitz.com/game/replay.pl?game_id=1815859&pbp_id=3317365 (RG has a blocking target)
http://goallineblitz.com/game/replay.pl?game_id=1814672&pbp_id=2609748 (RG has a blocking target)
http://goallineblitz.com/game/replay.pl?game_id=1814672&pbp_id=2614785 (LG and RG nobody to block)
http://goallineblitz.com/game/replay.pl?game_id=1814672&pbp_id=2615130 (LG and RG on steroids with nobody to block, ie RZ freak)
I think that each position on the O line has a distance to travel to form a pocket. OTs have the farthest distance to travel. Strength DEs are having a good season imo because OTs drop back to where the QB is and the DE just has to slightly push the OT back to get the sack.
My last replay shows that it is possible for the Gs to help out with a boost to their skills. Of course sometimes double-teaming a D lineman makes the situation worse. lol
Personally, I blame the QB and how he moves in the pocket for most the sacks made by strength DEs this season.