The big issue is they don't specify well if a cavalry unit is an actually capable melee mosh-pitter or a shock cavalry unit. With Kislev if its not on a bear it's shock cavalry, full stop. Dervishes are extremely fragile and are meant for skirmish. Winged Lancers are okayish shock cav, and Griffon Legion is your Big-Boy-Fancy Shock horses. Except they leaned so heavily into the bear theme that the previously iconic Legion unit is now just.. present.
A lot of the series cav is pure shock if its not a monster so you're almost always better off building Monstrous or Monstrous Cavalry to be your hammer units. Even Blood Knights and Dragon Princes who should be the cream of the cavalry crop have sub-par trades if you don't cycle them. I'm also not sure what LL buffs your cavalry if any of them even do. I think Boris goes for bears and Tzar Guard, Katarin is all about her ice units, and Kostaltin buffs Kossars I think.