Man, I thought this was going to be the secret ingredient to fix my team, but it was not the case. A few caveats:
1) I'm using FM23
2) I switched after game 3 so there was no preseason build-up
3) I have a below average team that was built for a 4-3-3 (not a huge deal but the tactic familiarity is low)
However, my back 3 was in disarray constantly and despite loads of possession, every highlight was going the other way. I started with the tactic as you laid it out and then made adjustments. Only after going with a very low block on defensive was I able to s-house my way to a 0-0 draw against another bottom feeder.
My biggest problem was getting killed on the flanks, especially on crosses that switched field. My opposite WCB was sitting dead in the middle of the pitch while a winger was wide open on the outside - boom, goal against.
You obviously (playing with a very good team) had success with this but how did you deal long crosses?