I think we are overthinking it here. Last year our only explosive receiver was X. In the second half of this game we only threw one ball to him which he dropped, and no targets in the 4th at all. The rest of the time he was used to take the top off while everyone else got one on one. The result is big plays for Mitchell, Whitt, and Sanders. Last year we tried to put Cain in the role but he was constantly running bad routes or just not giving a lot of effort. We seemingly had no other option which had us targeting X a lot more than we should. You add AD and all the sudden we have two receivers that are a problem one on one. The field is now wide open and this helps Quinn see where the ball needs to go.
Defensively, we were good last year but our weakness was our lack of pass rush. All the sudden Burke and Sergio Kindle Jr show up and we have 5 sacks in a single game and 7 in two games. Last year we had 27 sacks total. If we keep at this clip we will have 42 by season's end.
We've simply added better players and are benefiting from their productivity. There is no magic elixir. We play that game last night with no AD, Burke, and Hill and we lose.