*Fingering issues* i e what finger you chooses in a certain sequence of notes or for a specific chord no doubt primarily is an individual matter and because of that all these suggestions in tutors are rather meaningless. Regondi by the way judging from his own examples for good reasons may be suspected of having had unusually thin and flexible fingers...maybe part of a somewhat androgynical constitution.
Nothing dogmatic in that...

Concerning the connective tissue links which tie the fingers 2,3 and 4 together this is a general anatomic condition expected to affect EVERY normal individual but possibly there may be abnormal exceptions. The consequence of their presence is so obvious however ( you can easily domonstrate it by yourself - if necessary just ask me about some simple experiment...) that it is reason enough to skip using the fingerplate unless playing very slow tunes or if insisting playing like Charles Wheatstone prescribed - having BOTH 3rd AND 4th fingers on the plate and using just 1st and 2nd fingers for button work