Yea, it does seem like we often have this angst in the first 4-6 games over M3's teams. For a couple of years there, they had difficulty with Lovie's Bears early in the season (James Jones fumble) and usually played better against them later. To M3's credit, his teams usually get better as the season goes on. If it's because, as max often mentions, he's actually very good at in-season adjustment or because, as 31 has suggested, M3 sets up plays to troll later season film reads, they do usually look more competent later in the year.
I'm not too worried yet. Ford Field has been tough for the Packers and the Lions usually seem to be better earlier in the year but then slowly fizzle in the back half.