Dunkirk seemed to go as far as they could to make the war seem terrible and worthless.
There was almost no context, and nearly all the proponents seemed ineffectual.
In their favor, a lot of what they showed was historically accurate, and at that point, Britain was losing the war rather badly.
I couldn't put my finger on it but I think you did. Also, as I remember, the characters all looked alike, which made it hard to follow.
The Nazis attacked by air and shelled the beach and rescue fleet incessantly (totally missing from the film). 60,000 French troops along with the British "lost battalion" fought a valiant rear guard action which delayed the Nazis advance and provided the time needed to rescue the hundreds of thousands of troops... totally missing, Nolan doesn't even show one single Nazis German soldier, not one! Disgraceful.
One more thing, by in large, most of the British troops were presented as fearful cowards, who just wanted to get home. While true in some cases, there was a near lack of bravery courage or dogged determination to survive and escape to get back in the fight presented.
And the civilian rescue fleet literally made up of over 700 small craft, of wich more than 100 never made it back. Nolan presents a mere handful of small boats, it looked pathetic, no scope or scale. CGI, tastefully applied and coupled with the small number of actual boats used could have provided the scope, and the grand scale of the operation. It was a missed opportunity.
If you want to see scope and scale of historic events done right watch "The Battle of Brittan", The Longest Day, Saving Private Ryan, The Pacific, Band of Brothers. To name but a few.
If you want a genuine, historic overview of Dunkirk see:
http://dunkirk1940.org/index.php?&p=1_187
I like Nolan but while the visuals were stunning, Dunkirk the film fails on so many levels.