Don't have to compare two different groups to see that a different style of defense is being employed.
For example, Flores has his players play a lot closer to the line than Patricia does (part of this "aggressiveness"). That's one of the difference in their styles which has nothing to do with personnel or "schemes."
I'm not so sure about that, entirely.
It was crystal clear from the get-go that the DL personnel MP had to work with in 2017 were abysmal against the run, even when the style and scheme were cautious/conservative. Being more aggressive seems like it would only have made that worse, especially with the state of the Line-backer group.
So, I agree with the notion that the upgraded front-six personnel Flores has to work with in 2018 allows him more leeway to be aggressive. That said, I don't think it's merely the one thing or the other - the difference in personnel v. the difference in coaching/play-calling style aren't necessarily mutually exclusive.
Also, I wouldn't project the "Flores defense" to be quite as aggressive when the real games start as it was last night. As Chatham and others have pointed out, BB's defensive philosophy has been to play contain/bend-don't-break when the ball is still inside the opponent's 45-yd-line, and then become more aggressive when (if) the opposing offense approaches the red zone - manage what the offense is trying to do, avoid chunk plays, pick your spots to let the dogs out - especially in the early parts of games. I really don't think that's going to change much under Flores. OTOH, I also think that aggressive calls are going to be far more effective when they're made, mostly due to personnel changes (and player development).
Last night's more aggressive style was, I think, a matter of letting the dogs out to blow off some steam and to see how they work together (damn relentless, snarling wolfpack it seemed to me) - and also to see how well the guys behind them would be able to clean up (very well, I thought - and Crossen was excellent in that regard, especially in edge-contain).
BTW - on re-watch, I want to focus on #58 (Davis). My real-time impression was that he's quietly very good and definitely looks like he belongs in the edge rotation on the 53 for both his run-D and pressure contributions.