They have a multi-tier assessment system, that I think just includes:
* [[ https://ru.wikipedia.org/wiki/%D0%92%D0%B8%D0%BA%D0%B8%D0%BF%D0%B5%D0%B4%D0%B8%D1%8F:%D0%94%D0%BE%D0%B1%D1%80%D0%BE%D1%82%D0%BD%D1%8B%D0%B5_%D1%81%D1%82%D0%B0%D1%82%D1%8C%D0%B8 | Добротные статьи ]] (good articles), template at [[ https://ru.wikipedia.org/wiki/%D0%A8%D0%B0%D0%B1%D0%BB%D0%BE%D0%BD:%D0%94%D0%BE%D0%B1%D1%80%D0%BE%D1%82%D0%BD%D0%B0%D1%8F_%D1%81%D1%82%D0%B0%D1%82%D1%8C%D1%8F | Шаблон:Добротная статья ]]
* [[ https://ru.wikipedia.org/wiki/%D0%92%D0%B8%D0%BA%D0%B8%D0%BF%D0%B5%D0%B4%D0%B8%D1%8F:%D0%A5%D0%BE%D1%80%D0%BE%D1%88%D0%B8%D0%B5_%D1%81%D1%82%D0%B0%D1%82%D1%8C%D0%B8 | Хорошие статьи ]] (really good articles?), template at [[ https://ru.wikipedia.org/wiki/%D0%A8%D0%B0%D0%B1%D0%BB%D0%BE%D0%BD:%D0%A5%D0%BE%D1%80%D0%BE%D1%88%D0%B0%D1%8F_%D1%81%D1%82%D0%B0%D1%82%D1%8C%D1%8F | Шаблон:Хорошая статья ]]
* [[ https://ru.wikipedia.org/wiki/%D0%92%D0%B8%D0%BA%D0%B8%D0%BF%D0%B5%D0%B4%D0%B8%D1%8F:%D0%98%D0%B7%D0%B1%D1%80%D0%B0%D0%BD%D0%BD%D1%8B%D0%B5_%D1%81%D1%82%D0%B0%D1%82%D1%8C%D0%B8 | Избранные статьи ]] (featured article), template at [[ https://ru.wikipedia.org/wiki/%D0%A8%D0%B0%D0%B1%D0%BB%D0%BE%D0%BD:%D0%98%D0%B7%D0%B1%D1%80%D0%B0%D0%BD%D0%BD%D0%B0%D1%8F_%D1%81%D1%82%D0%B0%D1%82%D1%8C%D1%8F | Шаблон:Избранная статья ]]
The template lives on the article page itself. So I think to make PageAssessments work we'd just need to pass in the article name, and have each template transclude the meta template. I don't think there is any concept of article "importance" on ruwiki, nor are there any WikiProjects.
We may wish to refer to the ORES team/code regarding any other classifications, as it has [[ https://www.mediawiki.org/wiki/ORES#Support_table | WP 1.0 assessment support ]] for ruwiki.