OLD JEDI 72
Using alcohol for kindling in winter is very wasteful. The guys couldn't use it at the cedar because the flask was left in the tent. I'm talking about this - the assumption that alcohol was used for kindling during the hike by mistake. Some groups took dry fuel (aka dry alcohol) or strips of organic glass or plastic for kindling.
Your logic is flawed, who would care what was wasteful at that time? They were half-dressed, lacking footwear, and just walked a mile downhill over rocks and were freezing. Also, who cares about the flask in the tent? The fire was at the cedar, not the tent. What I'm saying is that someone had some kind of accelerant that wasn't accounted for. They had wooden matches but who had enough foresight to have these other items you speak of when they didn't even have shoes in some cases! Which made me realize something else, how did they strike these matches? Were they Ohio Blue safety matches?
I think we discussed this at the begining of this year because I went to a local pine wood to make sure that I wasn't going mad . It was wet and slight snow about -1 degree Celsius.
It took two attempts of breaking small branches at shoulder height, the donor trees were about 7 meters tall . The two branches were a bit thicker than a pencil or pen. I broke the branches exactly at the base of the branch and the trunk of the tree. There was considerable amount of sap , I brought a lighter to the end of the branch at it took light in two to three seconds. It stayed alight , popping and crackling giving off a beautiful smell . This I suspect is what they will have used . We also know they had various pieces of paper in their pockets , they may have had more and used some to start the fire.
It might be you are thinking that all they had were long log branches of a diameter of 90mm as reported as found and then how do you light such a big log without some sort of accelerant?.
It is most likely that they broke a lot of small branches , either off the dry wood of the cedar and or other branches in the area . As is standard for anyone with basic outdoor knowledge of starting a fire , small twigs , bigger twigs , small branches , bigger sticks then logs . A small piramid of weathered cedar or pine , perhaps some birch bark and you have a decent starting point.
I don't have the experience of extreme cold fire starting and what parts of the trees are best . There are plenty of videos on YouTube about starting fires and how to build them. However, a number of years ago I did learn how to select trees / wood in my own environment. We surfer from the wet which is a challenge but can be done.
I have managed to light a fire from 100% material around me during early March and a striking rod. One strike of the rod ( spark ) and the fire just took off.
At least two off them had matches on their person , I would assume that the striker would be with the matches. It takes effort and knowledge but can be done . It is a strong reason for argument about choosing the cedar and it's dry branches for the main heat source. It would take an age fumbling about in the snow and dark to find a suitable dry or dead tree . They had nothing to cut large dead wood, the dead wood on the ground may have had water frozen inside which would be of little use.
The Mansi chum ( picture of the cut trees stacked in a piramid ) which is not a chum may have been the fuel source when the Mansi travelled that way, the vertical stacking allows the wood to dry as does the exposure to the wind.
I don't think there's anything strange or difficult about them starting a fire, although a fire and den next to each other is the ideal.