How else would you assess whether his or Yates' performance was the most impressive which was the origin of the discussion?
I thought it was pretty clear that Dumoulin's time was better? I mean, his time isn't too far from the best German women on that distance. Yates' time is pretty far away from the best German women. That's how I'd measure it.

Honestly, simply by looking at it and comparing to the times of each discipline I know.
Anyway, in my eyes a comparison doesn't make that much sense because those were different events and we don't have a clue how much effort they put into it (Dumoulin doesn't seem super-prepared or caring) and a marathon, I think requires more specific preparation if you want to do well than a 10k run, which can be done with a decent time by pretty much everyone who's well trained "along the way" (Don't mean that anyone can run Dumoulin's time, just that for a similar result you need less specific preperation.) And, more importantly, maybe you can try and compare a 10.000 meter effort to a marathon because some runners switch to marathon in the long run... but no elite athlete switches from 100m to the long distance runs, the physiology is simply totally different. So the only thing that could be measured is "where would that leave you in terms of placings in the world" - but I don't think the amount of people who run 10km and marathons is the same, so you would have to adjust it accordingly when for instance, like in recent times, the number of marathon runners has become stellar or when it goes down.
Basically, in my eyes it's pretty clear from the first eye test that Dumoulin's time is better in comparison, but to do a marathon "in between" is just a lot harder, so I'd just say those are both very good runs and more cannot be determined at this point.
And to be honest I sometimes think that this forum is a bit obsessed with ranking and comparing things that simply cannot be decently compared because we are lacking parameters, factors and simply quantity of material to make it significant.