I guess first things first; DSC2 isn't designed as a Pass/Fail type exam, rather an ability for "candidates to demonstrate their knowledge and competence in legally, safely and humanely culling deer and dealing with carcasses hygienically". So comparing it to exams at school is not really apples to apples.
If that's the aim of the qualification then it's hard to see how you could demonstrate either of these on the basis of just one successful stalk. Personally I feel three provides the right balance between meeting the objectives of the DSC2 and not being too onerous, costly or time consuming.....and no prizes for the first to come back and argue the "costly" statement
Does it make you a stalking ninja - no.
Does it make you better than someone with a lifetime of experience - not necessarily.
Does it mean you've demonstrated knowledge and competence - yes.
Does it mean that you can rest on your laurels - no.
Now given that the DSC2 is out there and established (4,004 completed as of today) why go and invent some new measure?
willie_gunn