Best Defensive Scheme for 6v6 Flag football?

[Colombo]

Ok well it's the season for intramural flag football, and I'm arguing with my manager about the best defensive strategy.

Rules:
6v6
You need 2 WR, 1 QB, and 3 O-Line for offense
You need 2 CB, 1 safety, and 3 D-Line for defense.
O-Line can go out to retrieve passes (basically, they are all tight ends). However, there needs to be 3 people on the line to start.
OL's can not use their hands. It's basically like a basketball pick, but they can move their feet.



How should we go about designing a defensive scheme here?

I was thinking about dropping the DT back to play linebacker. One play I thought of was this.




This play takes some pressure off of the QB, but allows the defense to defend against quick dump off passes to the O-Line, or cross patterns by the WR. The team manager isn't a huge fan of this strategy, thinking that we should rush 3 guys at the QB to keep maximum pressure on him. However, I think this allows the O-Line to just receive a quick pass and run long. Obviously we aren't going to do the same thing every time, but what are some of 2p2 thoughts about designing some quality defensive plays?