Thing is, with a consul or triumvirate system (you can’t have more than one “dictator”; all of these terms are from Ancient Rome anyway so let’s use them properly), if any disagreement arises between the 2 or 3 leaders, it will develop a new instability where there wasn’t one before. Or else, one of the 2-3 leaders will start to dominate the others. Even without turnover the dictator system is more stable. In fact the only benefit of a consul or triumvirate system might be the stability and continuity under turnover.
And a project that starts with just 1 BDFL, and works fine & builds sth people "love", it'll continue working fine with that 1 BDFL.
If, however, replacing one of those 3, or adding another BDLF to a one person project — I'd think that by default, that won't work.
... Unless the new person has worked next to the earlier BDFLs for years, so the previous BDFLs can be ok certain s/he is "the right one"?
Whatever works fine, works fine — the risky thing, is introducing a change (a new person)?