It's all opinions but fwiw, I think too many people see the game as black and white of attack vs defence, I agree I think we were setup too defensively minded, but Skipp got forward quite often. Out of the 3 man midfield, Ndidi plays more defensively, Skipp goes forward and Winks plays between the two.
This idea that just because we subbed on some offensive midfielders and we started creating chances that we should have started with that and would have got a better result if we did is just oversimplifying tactics.
With a 3 man midfield of Winks, Skipp and Ndidi we were still defensively overrun, if we had Bouanotte on from the beginning we very likely could have been even more overrun in midfield which easily could have cost us more goals in the first half.
I understand peoples frustrations with Cooper wanting to setup with a more traditionally "solid" midfield at the expense of creativity, but that doesn't automatically mean it's the wrong decision. He could have started with Bouanotte and we go into half time 3-0 down, in the end we came into the 2nd half still in the game vs a Champions League side. Was it frustrating? Yes. Is throwing attackers on from minute 1 always the answer? of course not. Football isn't black and white. I hope we find a better balance too, but my personal opinion is that if we had dropped Skipp, Ndidi or Winks we would have been even further behind with how badly our midfield was getting overrun.