As always, there are moves that can be made (trades, etc) that shake up the formula a bit. But focusing on just internal fixes, here are a few things that have gone wrong so far, that I'm not ready to assume are "just the way it is now". They might be as bad as they've looked so far, but i'm willing to give it a few more weeks before I just accept it as inevitable:
1) I'm not ready to say Hightower has peaked for the season. It could be that he's lost a step, it could be that a change to his role is in order. But it also could be that he's regaining confidence in his body after his injury, and will look more confident and decisive in his movements as the season goes on. We'll see.
2) Michel is a rookie who missed much of camp. I expect him to get better as the year goes on. How much value that adds remains to be seen, given we have other guys who do similar things on the roster, but options are always good things. Also, I'm not giving up on his receiving ability due to a couple of drops.
3) There are two HUGE potential weapons coming to the offense in the new few weeks. Both carry (different) question marks, but both have the ability to make this offense completely unrecognizable from the version we've seen so far. Edelman not only is a weapon himself, but Brady is different when he has him. He's Tom's safety blanket, even more so than Gronk I think when he's out there. And Gordon... well, there's a LOT to still see about Gordon, so I won't rely on that. But again, potential.
4) Flowers coming back, as we've seen in some twitter posts, seems to make a huge difference. Keep him healthy, and I think Wise is making a similar leap this year. He showed by far the most energy against the Lions in the 2nd half.
5) Bentley is going to keep getting better. He's making rookie mistakes, but those will tighten up. He's shown he has good instincts, can tackle, and can take advantage of turnover opportunities. His development will improve the defense, especially if #1 comes true and Hightower rounds into form.
6) While they haven't been great in some areas, I still like our secondary. I feel like our biggest problems right now on defense are controlling the line of scrimmage, and losing on 1st/2nd down. I don't expect any secondary to consistently cover receivers when they only need to get 3 or 4 yards for the first. It's just a tough position to be in. If the front improves, the back will start to look like they should.
I don't think (or even need) all of these things end up working out. They're just examples of things that can realistically improve with hard work, coaching, and a bit of luck, without having to make any major trades.