If we buy another striker, it should be someone who's capable of challenging Aguero, not just a backup. You don't see Barcelona buying backup strikers. Maybe young players that aren't quite the finished product. Ideally we want a forward who is world class in a number of forward positions, like Neymar, Messi, Muller, Ronaldo, etc (hopefully Sterling can become that in time). I really like Vardy and he brings something to the team even when he isn't scoring, similar to Tevez, but he's never going to match Aguero. Do we really want to blow another £30m on a backup striker? Vardy might be great for Leicester, but would he really be able to replicate what he's doing from the bench in a team that's built around a different player, knowing that he's never gonna be first choice? In his favour, he's a better fit for our system than Bony is, because he's more similar to Aguero. But one thing you miss if you swap Bony for Vardy is the ability to change things up a bit tactically, since Bony offers something a bit different.