Yeah, we try to copy them, but we try to copy their 2 TE sets and obsession w/ CB's. Here's some of the things that really make them successful.
1. Continuously draft OL and DL.
2. Make sure to have replacements in place for players who will want a huge salary.
3. Do the opposite of what most of the NFL is doing. This allows you to find useful players all over the draft. Belly's 3-4 wasn't everywhere, so he was getting players who fit his system all over the draft. When the NFL switched to the 3-4, Belly went back to the 4-3, so he's still finding useful players all over the draft. He was doing that 2 TE set, so when everyone started switching, he's now going for WR's and is using a pass catching RB profusely.
4. Even if they don't play more than half the time, make sure to have a huge dude for the middle, to put a stop to O's like the Rams. Stop that run up the middle, and it's going to be a bit more difficult.
5. Always have a good stout OL in place. Always.
6. Don't overpay players. It kills you pretty quick.
Anything I missed? I know, I know, it helps tremendously to have a top 5 all time HC and QB, I get that. And that's a huge part of why they win. However, there are other things that can be done.