Ignore Kendall about small divisions of light cavalry . . . after all, he is the person who conceived and ran a division comprising just two small cossack units !! And very good it was too !
Personally, I am a fan. And I use small divisions of two light cavalry units often - indeed, my 1812 French mix for both the NZ Nationals and the Melbourne competitions this year had such a division (comprising 1 SD and 1 AD unit).
A division of two AV LC units would be even better than my mix for either delaying or attacking as the terrain and opponent permitted. A division like that is just great at helping you to set up the shape of the game. And having the ability to shape the game is invaluable in my view (and also hence my enthusiasm for using Exceptional Corps Commanders !).
But, and FWIW, Kendall is pretty much right on the money about the lack of punch with LC - they are really good for striking from a reasonable distance at an ill-prepared opponent; and really really good at taking advantage of an already weakened opponent; also great in the contact zone for cramping an opponents options; but not quite so good assaulting against any sensible formed infantry in good order. Sometimes, also, you can 'bounce' an unwary or poorly deployed opposing cavalry unit or two cos of the 10MU reach. But, in my LC horde army mix I often found that it was more of a 'dance like a butterfly, sting like a butterfly' mix. Plus, you should think about how they will play when defending - that will require them to fill a different role again.
LC are not at all crash-bash like the shock heavies

!!