I guess we need to wait a few weeks for the ground to freeze fully enough to allow the traverse of Russian armor into Ukraine; if they are going to go, they will go then (having your tanks sink in mud is still thought to harm their usefulness).
We have a conventional bomb that has a yield of 11 tons of TNT; some call it MOAB - the mother of all bombs.
They can be delivered by C-130 aircraft.
It would seem to me that ten C-130/MOABs should be given to the Ukranian air force.
That would be 2.2 pounds of TNT per Russian invader.
Sounds about right.
Alternately, if that many dead Russians sounds like NATO over-reach, I suggest we invite the Russians to join NATO.