Borda, Margins, and Winning Votes all agree that A should be the winner, but it seems to me that the "Futile Approval Candidate" C is a decoy that confuses the issue. Remove C, and the obvious winner is B, the Bucklin winner.
A Futile Approval Candidate is one that would never win under approval even if the approval cutoff were placed immediately under his name on ever ballot possible, i.e. on every ballot except those on which he is ranked or rated dead last.
I believe that Futile Approval Candidates should be eliminated from the ballots as soon as they are detected, so as not to confuse the issue further.
To its credit Cardinal Pairwise gives the win to A or B depending on whether B is closer to A or to C in its rating by the third faction.
Forest ---- Election-methods mailing list - see http://electorama.com/em for list info
