To O.P.: both of us had the same idea, but rather different execution. I gave up this tactic in the end as I wanted more possession in the middle of the pitch, and I used a sweeper, with default marking and standard strategy. Default marking made sure the sweeper was zonal, and doing his job properly, and the two players above him were putting strikers in their back pocket with man marking, but using man marking anywhere in the field means lowering the tempo, or face consenquences of tired CBs after 60 mins of match, hence the standard strategy. You are doing okay, and going in the right direction but the tactic still needs work.
Post your tactic then plz? I've tryed ovro's and would love to try yours to see if it is better as you claim. Thanks in advance. .