This is just from memory, but the way the Packers won the SuperBowl in 2010 was by being outstanding in a few areas and solid enough in the rest, no glaring weaknesses. If I recall correctly, not having major injuries at any one position helped as well. So yes, you are right, in 2010 the TE position was adequate enough to accomplish this (Finley was on that team for 5 games btw). But what happens, when you lose a WR or two, like in 2015? If you don't have a solid TE, it compounds things. What has hurt the Packers since (IMO) is having a position or two of weakness, that ultimately exposed the defense or didn't give the offense enough fire power, this has either been with starters or lack of depth. I don't expect the roster to be 3-5 deep at every position, but I would like to see a little less dependence on rookies, UDFA's and guys who have had their stay in Green Bay extended a little bit too long, simply because TT and the Packers are still waiting for them to develop.
I know you keep bringing up "replacing Shields" is an unreasonable expectation. While you are probably right about mid season, what was wrong with trying to replace him in the off season when you have access to top CB's via Free Agency. If we lose Aaron Rodgers do we just say "well....Hundley is our man and we are sticking to him, no matter what"?