The debate so far has focussed on the merits of Buchanan and his multi-captain theory. This misses the point, because it should really be about Ganguly and the Bongs.
The four teams that failed to make the cut for the semi-finals in the first IPL season were those led by the seniors - Tendulkar, Ganguly, Dravid and Laxman. Bangalore and Hyderabad wasted no time in replacing Dravid and Laxman as captains, even though they continue to play for India at least in Tests, unlike Ganguly.
It's arguable how much of Ganguly's success as captain of India can be attributed to his leadership, given the quality of the team that played under him. But there can hardly be any argument about his failure as captain of Kolkata Knightriders.
SRK spent more money than Jaipur, Delhi or Mohali, but his team did not do half as well as them. And it's not just money that he invested. Unlike Mallya's think tank which selected a Test team to play T20, Knightriders had some brilliant selections, such as Sri Lanka's mystery bowler Ajantha Mendis who later bamboozled India in the Asia Cup and a Test series. The Mendis selection was totally wasted, however, because Ganguly picked him in the playing eleven for only one match - so much for his astuteness as captain! Even the talented Pakistani bowler Umar Gul was underutilised, coming into the picture only in the latter half of the tournament by which time it was too late to turn things around. Instead of playing Mendis or Gul, Ganguly kept relying on Mohd Hafeez's all-round abilities, and this was a big blunder. Besides, Ganguly's own batting form was a handicap for the team.
Given all this, it would in fact have been a surprise if Buchanan had continued with Ganguly as captain, especially now that he is out of international cricket and can hardly be expected to perform even at the level he did last year.
The problem with dropping Ganguly as captain, however, is the inevitable Bong backlash that follows. Apart from Buchanan himself, Ganguly's replacement as captain would face the wrath of Kolkata. It seems to me that is the real reason why this elaborate multi-captain charade is being played out - it has more to do with fans than cricket. Think about it - with so many captains, and Ganguly being retained as one of them, whose effigy will the crowd burn?
Meanwhile, behind the scenes, Buchanan can go ahead and work out team strategy with those he thinks are capable, and entrust one of them with leading the side in the field. Quite an out-of-the-box solution actually. Greg Chappel must be kicking himself for not thinking of it.