the answer is.....it was a once and a lifetime thing and the right people were in the right place and time to make it work.
the big three of the original group (flair/arn/tully) had such a great chemistry
nobody has ever topped it
you could replace the ole character with various different people (lugar, sid, barry) but in the end, it was the above three who made the machine go. once tully left, it was never duplicated.