Yeah it's the sorry tale, the rotary came first followed some time later by an interest in cylinder mowers. 4 mowers in a yard that's 10m x 3m is a bit of overkill though and apart from the 14" with the Briggs they all work.

so the tally so far is
Honda=3, all working
Briggs=1, non working or unworking, whichever is more PC.