I stumbled upon the graves first when I was going around the area... no wonder Filaev and Chenov sounded so familiar as soon as I started seeing their names through the side quest.

I was strongly rooting for their survival as I lived through their battles, alas I was met with a wistful realization as I the grave came into view while riding the kuurata.
My heart breaks for these 5 in a humble unit of the Ratnik -- Filaev I will remember you every time I eat grilled ribs, always.