Of course the plan wasn't to have Hummels in one on ones against Mbappe. But when you're behind, you have to risk something. And Pogba and Mbappe are more or less the least combination of players you want to face under such circumstances. The game took a perfect turn for France with the own goal, like it or not, and it played into their cards. Obviously they're going to create chances on the counter over 70 minutes waiting for counters while the opponent has to push forward. The game would've looked completely different if the first goal didn't happen. And yes, it makes a difference if a goal or respectively a chance came from an easy mistake or from a world class pass that maybe 5 or 6 players in the world play on a good day. It makes no sense to ignore that Pogba and Mbappe simply had brillant days.
I think it is looking for the fly in the soup to pick Kroos out in those goals. Yes, he could've been in a better position but that's always true when you concede and there's no team that allows no chances. So far Kroos has done a very good job, if you ask me, and we're looking much more stable in this formation than I expected.