It's never that simple. Sometimes taking a forward or wide player off for a midfielder gets you more of the ball, and you become more attacking and create more chances.
If we'd stayed as open as we were 1st half, we could lost that 5-0. You might say 'what does it matter?' but it does matter. He was trying to get us control of the midfield and get another striker in the box in the hope that we scored next and made a game of it. It was a good decision, in my opinion and worked. Unfortunately one of our strikers is a young lad struggling a bit and the other is a loose cannon with very little technical ability.
Hmmm. But what about pace and width? Have you watched much premier league recently? ;-)
I apologise. You were right about pace in defence but most were banging on about wingers. It's interesting though the number of myths that have debunked recently.