@jhungary
On whether they can reposition their troops. So far, the reports are of troops that were hanging in their rearguard, or weren't able to be deployed into Kiyv for whatever reason. By doing that, they make themselves moderately vulnerable to breakthrough.
We need to note that this is not a rotation, and these weary troops from Kiyv front will be going without rest to the East of Ukraine after few days on a train. This also leaves them without an opportunity to use these troops to rotate their troops on frontlines.
Pulling their front line troops from near Kiyv is out of question, because Ukrainians will have a turkeyshoot at retreating troops.
They had extreme trouble deploying the force of this side into dense forests on Belarus borders, and it means they will have equally bad logistics problem during the retreat.
Retreats are often costlier than advances, because dangers of chokepoints getting under artillery fire are at least doubles during retreats. It's one thing to suffer from chokepoint congestion during offence, when your advance party keeps the enemy occupied 30kms-40 kms away, and completely different when the enemy is right there, shooting you in the back.
They will likely have to abandon a lot of damaged, but still recoverable armour, ammo from emplacement, towed weapons left without tractors. Wounded soldiers take more space than ones who can seat.
The railways are said to be disrupted on Belarusian side, and Ukrainian/LNR/DNR connections with Russian rail were blown up over past weeks in the East. Even with rail, the evacuated armour will take weeks to load on trains to Russia, refit, and redeploy.
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Now, they want to deploy those 10-20 BTGs, or what's left of them to the West.
How?
They no longer have the option to deploy them at leisurely pace during peacetime, nor is the LNR/DNR territory is safe now. There is no ammo, and supplies for them there, as it was already used.
They will also have to repair/reorganise broken BTGs. Get new armour/artillery for them. Appoint new officers from somewhere to replace KIAed/WIAed ones.
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In other words, they are either off for good, or they will be redeployed half-broken, without serious armour, and supplies. In the later scenario, they will only be able to provide 20 BTGs of very light infantry, or 12-15 ones on basic, and obsolete armour from Russian reserves.
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The biggest wutang not discussed yet, is that they will be redeploying 15000+ broken, and demoralised troops who thought that they will be "going for military exercises," into a place they know will be a complete meatgrinder.
I bet, there will be surprises.
They even couldnt count further than 5 cause they need the fingers of the one hand to count the fingers of the other hand 
Medium term means what? 5-10 years? Ooohhh, so how will Germany compensate russian gas end of this year? And the next years? If Germany do not pay in Rubles? No Rubles -> no gas! And there is no other gas delivery in sight.
