I must be slow today but I cannot understand my answers: cruel Mr Green = heartless --where does Mr Green come in?? Am in disgrace with the lady = she---why?? stuff a cow = jersey-- does jersey mean stuff? Generally speaking I'm not impressed with the setter - I think some of the clues are too vague.
The implied method of solution, as SHAME - AM = SHE, is a relatively recent genre of cryptic clue. However, it is becoming very popular with setters in order to produce short answers!
Love them or loathe them, I believe they are here to stay.
These comments apart, the example given above is not well worded!
I'm familiar with the format - in fact I've set several such clues myself. But this is just plain wrong! For example it would need to take the form of "Woman who if penetrated by American would be a disgrace" (off the top of my head) to work, IMHO.