Possible strengths of a 4-3 defense:

[Gageac]

A retired defensive coach with 4-3 experience explains some of the evolution of the 4-3 and some of the basic advantages a 4-3 might hold in store for those looking for a more simple attacking and aggressive philosophy. Fortunately the coach is an ardent Oregon fan and once we again take the field he will be able to point out the particulars of what we can hope will become known as the “Oregon 4-3”.

http://fishduck.com/2016/02/i-fell-in-love-with-a-defensive-system/