Each of Wynn, Ferentz, Cajuste, Strange and sometimes Brown were overmatched yesterday, often more than one on each play. If one guy gets beat you can often step up or throw the ball away, but when two or even three are getting beat at the same time it is way harder.
Over 61 sacks (2009-2011), Brady's average time to sack was 3.1 seconds, so Mac is getting sacked significantly more quickly than that, suggesting that overall he is not getting sacked because he's holding onto the ball too long. Obviously any one play can be different - let's see what the all-22 reveals.