Yeah I should probably elaborate
Take a look at your chart, CO has about the right stats for a pokerstrategy TAG but maybe a bit too passive postflop. See what he raises after 1 limper, then see how many of those hands that you are behind. You'll probably find that the only hands that beat you are a higher pocket pair or a queen, out of all of the possibilities. You can download "Equilator" for free here at PS and I'll use it to better demonstrate the situation.
Let's consider this situation with MP1 excluded as he's gonna be holding a Queen even less often than CO.
His "range" or cards he's holding here are 66+,A5s+,A8o+,KTs+,KJo+
We enter our cards as 8s8h
Equilator says that you have 52.4% equity on this flop which basically means if you both had to go all in on this flop you'd win 52% of the time. Another feature of above 50% equity is that this means you can raise him! He is often going to call with A high after a flop raise and even a turn/river bet if he's got a flush draw. He will most likely only raise his hands that beat you. Observe his play against other players to confirm whether or not he can be deceptive.
If he's a reasonable player you can fold to a flop 3-bet OR if he raises your turn or river bets you can fold also.
The problem with a calldown is that MP1 could raise and then you don't know what's going on. In this situation with an open-limper I tend to ignore him as his range is even wider than CO's, however if u get a 3-bet from MP1 then I think you can fold also. In a 4-way+ pot it becomes a little more dodgy.
At 1/2$+ you have to start thinking in this manner of not just "I have second pair cause there's an overcard, I must fold to preflop aggressor" but how heavily his range hits the flop.
Consider a situation where you have QQ against a reasonable TAG, he raises in early position, you 3-bet and get capped. On a flop like KJx or ATx if you know he's playing perfectly straight forward you are destroyed by his "range" (AKo/AKs/QQ+) and perhaps can even fold the flop outright but if you hold something like 55in the BU and get 3-bet by the BB on a 7T6 flop you are still ahead of his range even though you have underpair as he's 3-betting a very wide range here "A2s+,K9s+,QT+,A3o+,KTo+,22+".
So yeah I also ran into these questions of "wtf? where do they say do blah blah with 3rd pair?" etc. when I switched to shorthanded which is a whole different ball game, but marginal situations still exist in full-ring as you can see. In short, think more about what possible holdings you are behind/ahead of and how many of his different possible hands will call you down if you're tossing up whether to raise or call etc.
Hope this wasn't too long but I felt the need
TerrorBlade