I agree, but I think this was bad media management more than anything.
I think that van Dijk (3 duels won out of 4 in the 90 minutes) was more of an issue than Quansah (4 duels out of 8 in 45 minutes). van Dijk wasn't involved enough in that first half, and he needed Quansah to dig him out when he gave a sloppy pass to the opposition in front of goal. Ipswich, rightly, targeted Quansah and Virgil should have been helping him out more. I thought he was pretty anonymous.
If Arne had said something like "I realised at half-time that I should have picked Konate due to the nature of the attacks from Ipswich" then he isn't calling Quansah out, he's saying it was a selection error. Then he can take credit for seeing it and not being too proud to change (remember how all the pundits used to suck Mourinho off when he made 3 subs at half time rather than calling him out for getting it so wrong in the first place)?
But the positive for me is that he made that change, it worked, and we'd won the game by the time Klopp would have finally got round to making his first subs. And we managed to win a game without conceding the first goal for a change.
Arm round Quansah's shoulder in the morning and we're all sorted. Then later in the season there'll be a game where he will likely make the reverse change when he realises he needs his second centre half to be better on the ball rather than physically beasting the opposition.