MoM marking works if you create the conditions conducive to it working. MoM requires proximity. I'd guess if you want t exploit weaknesses - attacking a narrow formation with a wide one then MoM is less than optimal. I'd further guess than MoM could perform better where you are mirroring (to some extent) an opposing formation rather than employing counter formation strategies.

And finally, Man on Man *sniggers*

Now grow-up/get a life/move on

PS. Just because I replied does not mean I care.