Yeah this game relies on 1 single thing and that is the ability of Justin Smith playing with an injury. Aldon Smith isnt some all time good Pass rusher, he is above average but most if not all his sacks stem from Justin smith taking double teams. It can be evidenced from the fact he has not got a sack since Justin Smiths injury, 1 of those games was against Arizone who gave up the most sacks in the league.

I dont care how good your D is, unless you get pressure on the QB it means nothing and without a healthy Justin Smith i dont know how much pressure they can get.