OK so I read "Here the key concept is that some of the effects of the large herbivores, such as eradicating trees and shrubs or trampling snow, will result in a stronger cooling of the ground in the winter, leading to less thawing of permafrost during summer and thereby less emission of greenhouse gases".
I know the big impact of trees and shrubs on albedo - in spring they absorb sunlight and shake off snow, which remains on flat grassland. But regarding trampling - compaction- I'm not convinced. Winters are long and summers short, so accelerating cooling by some weeks wouldn't make so much difference, as accelerating warming in the summer - that's when the gases are released.
Anyway what we do urgently need is global science cooperation to try to save the carbon and ecosystems of that permafrost, in that spirit such projects might help to thaw geopolitical obstacles.