Priority #1: Teach Tackling Fundamentals
I re-watched the game and counted no less than three dozen missed tackles, whiffs, and poor angles. There were half a dozen plays in which there were 3 or more missed tackles on ONE play. I did notice that in multiple cases the size of the backers had a lot to do with it--size mismatches and such.
Forget the scheme for a second, the ability to tackle was abysmal last night. That is just poor ass coaching, or drills.