This might be of interest to you :
https://www.youtube.com/watch?v=deK98IeTjfY
It's a video essay on ammunition stockpiles on Ukraine and Russia by the youtuber Perun. It doesn't paint a rosy picture per se, but it does directly refute at least a few of the points made by the author of the RM blog you linked.
Read [1] recently and it paints an bleaker picture than some other analyses.
https://www.russiamatters.org/analysis/whats-ahead-war-ukrai...