Overall, I don't consider the loss of Martin or Incognito anything special. They just aren't...it is just whether anyone can admit now... (Can we all face facts now and admit that Martin sucked and the only reason he started was so that the morons who picked him in the 2nd didn't want to look like total idiots...well, that failed...)
We have already seen Jerry and Clabo together on the right side, so we know what we have there already. And it isn't pretty.
McKinnie and Garner on the left is an unknown. Garner and McKinnie may actually play better than Martin and Incognito. The problem will be with stunts and blitzes and having to pass-off defenders. They haven't had much time to work together, so assignments may be an issue. I expect Monday may not be the best, but they should get better in a couple of weeks.
I think at least for pass blocking, McKinnie may be better than Martin; and Garner may be better at pulling and screens than Incognito. McKinnie though has problem with the run game, so the two of them together may not be really great in the run game. You have a relatively athletic guy now paired with a big powerful slug. Not sure how that pairing is going to work.