TN Work Permit for "Management Consultant"

I'm a Canadian Citizen, have been offered a job in the USA. I have MBA, MS degrees and over 18 years of experience and would like to apply under "Management Consultant" Category, and learnt its the most scrutinized category and get lot of rejections. Unless one has very strong experience letters and support letter from the employer, its difficult to get the TN visa.

I would highly appreciate and thankful if someone can please help me with the sample / format of experience letters required and support letter for "Management Consultant" under TN work category. Although, I have experience letters from various employers but they does not state same job responsibilities as required for the TN visa.
I just got denied my TN visa for Management Consultant. See my post...

Basically I have my BS and MS in Account from a US college. Been working as an “Accountant” for the Big 4s for the past 4 jobs. Recently got a job offer for “Management Consultant/Consulting” by another Big 4. The past 4 TN visas have gone without a hitch, they didn’t ask too many questions. This time they asked me why I should be qualified as a “Management Consultant” and how does it make sense to go from an “Accountant to Management Consultant”. Then they finger printed and shot my photo then refused me entry into the US. I asked them if I can reapply and they said sure. So I am working with my lawyers to make everything as concise as possible. From what I understand he wants me to tie my past work to my future work.

Tip: make sure when they ask about your new responsibilities you do not mention anything about managing a team. I said something about being a team liaison between the MA consultants and the accountant and he said thus sounded like a manager role and I should apply for a H1B.