Your comparing an article that has a huge amount of scholarly articles about its subject and one that has none. Secondly the way in which they are in the lead is completely different. It is not 'Battle of Midway where x,y,z happened'. It is merely linked to its own page. Considering there is only one or two sentences regarding the event in the body of the article, no it is not summarising. It isn't in the summary of the War in Donbass either and, unless I'm mistaken, we are only summarising that summary.