That doesn't mean we need to spend 35-40m on leftbacks alone. Neither of these two will be happy being 2nd choice.
We have other players than can cover LB also such as Trippier and Manquillo, heck even burn can play LB.
Nobody signs to be 2nd choice but that's the way it works. If your cover is ****e then you start losing when the 1st choice is injured. I'm surprised you don't understand this mate. We're not Mike ashleys nufc anymore we're a club that wants to be the biggest club in the world. All prem clubs have decent 11,s, but It's about being able to withstand injuries, suspensions the higher you go up the division.
Rotation substitutions and having another option for certain games is another strength you need.