I am on a Windows 11 PC with a 4090 and a 7950X3D

This has become noticable since getting the Cowardly Lion because of his AoE Fervor but Mavara's passive is supposed to be 50% chance for allies under fervor to join the attacks of allies under fervor. Varkos' passive is a 15% chance to join allies when attacking, or 25% for Dark Elves. This seems statistically impossible for Varkos to sit there twiddling his thumbs turn after turn after turn for 10+ turns in a row, only to do 1 ally attack to go back to twiddling his thumbs for another 10 turns. That feels more like he's entirely ignoring Mavara's fervor based passive and purely going off his own 15 or 25% from his passive. This isn't to say that chains of ally attacks don't happen, it's just that considering the probabilities, they happen less often than they should and the streak doesn't last nearly as long as the dry streaks.

EDIT: Literally have just watched Varkos not join a Fervor ally attack. 2 champions did, Varkos just stood there. So I'm seeing that it rolls per champion? But, other champions are joining significantly more than Varkos if that's the case