Don't put a dime onto the defensive side of the ball. With the current rules and officiating, and the emergence of QB's such as Mahomes, Allen, possibly Burrow, Herbert, and who knows who else will appear, who have great arms, legs, and heads , defense is becoming irrelevant. Belicheck with a good defense was helpless against us. Our "#1" defense was helpless against Mahomes. K.C. beat us with their very mediocre defense because of their offense.
It used to be good offense wins games, defense wins championships. No more. A topflight qb will generally beat a topflight defense. If your defense isn't going to win games for you, might as well have a mediocre one (K.C.), and put your $ and draft resources into protecting and enhancing your most important player. Do everything you can to build and improve and solidify the O-line.
It will help Josh, prolong his career, make your rb's and wide receivers better. With rare exceptions, defense just doesn't matter. If you don't believe this, show me one bills game this year that the defense won for us. I can't find one