The secret to this is using the players you've got to the best of their strengths & abilities. Far too many coaches try to shove players into schemes and/or positions they are simply not suited for, IMO. Gailey seems to be doing a really good job of plugging players in at the right positions and setting up schemes tailored to what they do best.
Like Bum said about The Chin, "He can take his'n and beat your'n, then he can take your'n and beat his'n." Gailey isn't there yet, but he has taken what most people considered one of the worst offensive lines in the NFL and with injuries and all, made it work.
Fitz has only been sacked 8 times in 7 games. Big Ben has been sacked 25 times, just for some perspective.
Fred Jackson is 4th in the NFL in rushing with 5.5 yards per carry and 103 yards per game average.
Those two statistics are due primarily to the outstanding play of the offensive line. A patchwork of guys who put their heads down, dig their cleats in and just get the job done.