Study does not seem to trust Russia's populations to be any help since Russia is not bound by any international laws of conservation thus requiring Finland and Sweden/Norway to have 2000 wolves or 500 breeding individuals between them. Unfortunately such amounts are not practical in any way. Both Finland and Sweden are having trouble with their less than 50 packs per country, amounts of 100 packs/pairs in Finland and 150 in Sweden are something that can not be realized, simply due demographics. Both Finland and Sweden are thoroughly inhabited outside the reindeer herding areas, leaving only fragmented areas for packs to live.
The fragmentation of areas.Link to the study in Nature