That is insanely awful and not in the least surprising. The best game the defense played all year was against the Raiders and the defense had zero (maybe 1?) penalties. Coincidence. I think not.
To the naked eye when the Chiefs corners have struggled with penalties it was because they were out of phase and panicking. To me, that means you have bad technique or you have corners that can't play in your scheme or assignment.
Against the Raiders. It was a simple go route down the sideline with Nelson against Ward. Ward stayed in Nelson's hip pocket, turned his body away from Nelson but still kept contact with him on his hip, found the football and got a PBU. No panic; just sound technique.