Davie,
I have been lucky enough to stalk your ground and seen some very impressive roe indeed, I take it you are referring to stalking ground like yours? If that is the case then I would say that as much experience as you can possibly get, remember qualifications do not equal experience. It is very difficult, if not impossible, to put a qualification level to qualify you to stalk deer in the urban environment. Having a level 1 on it's own does not add up to a lot as that can be obtained without ever shooting a deer, level 2 means that you have stalked/gralloched/lardered three beasts whilst demonstrating a knowledge of glands/hygiene etc but I would suggest that the level of safety awareness is heightened in the urban environment. You are much more likely to bump into pedestrians here than you are on the hill or in a wood, sitting in a high seat with your back to a main road, motorway, fields bordered by housing, 75% of the land being unshootable because of lack of backstop etc. It is not the environment for the novice, inexperienced or those without patience.
I personally do not think that qualifications alone will stand you in good stead for this type of stalking, I think that experience is the main ingredient, the qualifications will also come with experience, but mostly it needs the stalker to assess themselves, ultimately they know if or not they are up to job.
John