I see no aircraft in Mad Jocks list that require any more than a good look at the POH and a quick circuit with an instructor to get a competent PPL up to speed to fly.
Whilst this is true, you have to look at what is going on when most people change type, most are doing it in a school environment and often having changed school/club or joining a group where their capabilities are unknown. As an instructor I do conversions/checkouts for a couple of groups and this will vary from three or four trips (unusual, but has been needed - I am not including the 10 hours on type that the insurance company occasionally demands!) down to about 45mins chock to chock - the 45 mins I would agree was probably more than the guy actually NEEDED, but I would have felt I was not looking after the group interests if I had done less and not satisfied myself 100% that I had shown all that I needed to show and I feel for the types involved would be a minimum.
Anyway, what is the rush to do it in minimum hours?
I do think there are some ridiculous requirements though - I believe Goodwood require 5 hours to convert to their glass screen Cessnas, and flew a Harvard many moons ago that the insurance company wanted over 50 hours on aircraft over 250HP - but no requirement for tailwheel time (before the days of tailwheel endorsement)!