Well according to Wiki they have those numbers. That doesn't mean they can just send in waves of troops. There biggest problem IMO (from what I've read) is that the Russians are having logistical problems. If you can't feed and supply 100k soldiers there's no point in sending in more that you can't support.
In the US Army we figure it takes 6 support soldiers to supply 1 soldier in combat. It is amazingly costly and complicated. You have to literally supply these forces with hundreds of different items.
The Russians may figure they only need a 4 or 5 ratio, I don't know. Having been involved in numerous large operations I can tell you that supplying a fighting force in the field is a daunting task. Think of Williams Brice stadium 80k and CLA 18k being filled with 98k people and just the task of supplying them with 3 meals a day and (on average) a gallon of water each per day for weeks on end.
Now add to that spare parts, fuel, ammo, medical supplies, replacement vehicles, spare tires, troops to deal with the dead and wounded and on and on.
