I am really surprised at the score here. I will, in my scale give it somewhere in the range 8 to 8.5 (the extra marks are to balance for nay-sayers)
The story revolves around the heroine - a mare Lotna - in this case, and its various owners. All of them from the Cavalry - fighting their last stand against invading German Army during the WW2. Each of her owner is dogged by misfortune - getting killed in the war within days of having her under his control.
On first glance it looks as if she was the harbinger of bad-luck. But was she really ? Her original owner - had her from foal, in fact was the offspring of his own prize horse. And he didn't had any bad luck, if he died, which wasn't shown, must have been of old age. But once, with the Germans Army approaching, he gave the reins to the cavalry men (lest she became enemies property), the death started stalking - but along with the death there were also fortune/ luck. Each of the owners had it, before finally letting fate take over.
As an Allegory - it reminded me of Au Hasard Balthazar - another masterpiece - from another stable - and of course another animal, a donkey instead of the huge Arabian Mare.
In this case what did Lotna symbolise ?
As i see it - she symbolises the freedom, the pride, the spirit of a nation. It isn't limited to Poland, it is of any nation, any civilisation. One doesn't own or try to control it to his/her commands. If one attempts - the history would tell - from Alexander the Great to Napoleon to Hitler - with a great fortune in the beginning, untold misfortune (and death) will follow. The end also is apt on this angle - when the people get jealous and bicker over it, the result would be naturally what was depicted.
Probably it is necessary to watch it a few times and imbibe in, to get the message. Like Au Hasard, this too is told more like a story - which though well paced - or may be because of that - the message would be missed.