Perhaps the most peculiar thing is that it was an allied army (composed of, as described, Serbs, Bosnians, Bulgarians, Wallachians and above all - Hungarians, led by Louis I himself) that got defeated by the Turkish forces, yet the toponym is strictly specific (and reminiscent of a real battle we all agree took place in the following decade, for that matter): Sırp Sındığı...
Edit:
To throw some light on the locality in question:
This is the modern tri-border area of Greece, Bulgaria, and Turkey, with river of Maritsa dominating the locality. Marked settlements are:
1. Sarayakpınar (minor Turkish settlement with old name of Sırp Sındığı, as stated in Wikipedia article; however, on other pages I even read that Sırp Sındığı is supposedly a completely different locality, a village near Sarayakpınar)
2. Ορμένιο (Chernomen, the toponym Bulgarian sources relate the battle of Marica river with)
3. Edirne (Adrianople, which alleged allied army was going for)
Now, in the lower-left hand corner of the picture you can see the scale of the map. The straight line distance between Chernomen and Sarayakpınar is about 22 km. The battle of Maritsa river was fought at exact location of neither. It is only said that it was fought
near Chernomen. So, the area of two battles matches perfectly. Along with perfect match of scenario (one must simply wonder: how come Vukašin and Uglješa learnt nothing from the first defeat and allowed the luxury of loosing the same battle twice?
). And obscure data. And 7 years discrepancy on a time scale (which is all too common for birth, battle and death dates in the timeframe (what I mean is - we can often find that a person was born twice, thrice or even four times, browsing through various sources (a figure of speech, of course); it's the same with battles, so I'll repeat my opinion stated in the thread I've linked above: after date started changing, along with pumping up/decreasing numbers, unwittingly or on purpose, the battle of Maritsa eventually became two battles)).
Also, a funny thing. I had no idea about the degree of importance Turks used to give to us Serbs. Along with toponym Sırp Sındığı, I've also heard of Sirp Gazi in Asia Minor, named so in honor of heroic cavalry of despot Stefan Lazarević that took part in battle of Ankara in 1402.
Even more - the level of pertinence remains up to date - there appears to be
Sırpsındığı Sk (Sırpsındığı sokak, sokak meaning street in Turkish) in Istanbul.