England in a major tournament in the 78th minute are 100% guaranteed to already not be playing well
When I say plan B, I really mean plan F. You’re 1-0 down in the first knock out round of a big tournament, going out of the competition to some second rate team, the opposition has already done their take a striker off bring a DM/CB on trick, you’ve tried everything but you’re playing like shit, you’re coached by some English imbecile who isn’t going to make any real tactical difference (and even if he could he could never convey it to 11 other English imbeciles) so why not get Big Andy on and any time a winger / fullback / midfielder gets some space throw it in there and hope he wins it. Plan F already includes you bringing on Lacazette or Chicharito (Defoe ) and having him win duels is mostly about creating chances for those guys. Being England they’re probably already loading the box at that stage anyway.
But tbh I think it’s more about momentum. The placebo effect of the plan B if you will. You’re playing like crap with no hope and your heads go down, then as soon as he’s on and you’re doing something different and it works and someone gets a shot off or he challenges the keeper then you might think “hey this might work” and spirits will be raised.