Putin has his own army:
The new National Guard is suspected of being the new KGB army. As organized the new National Guard is taking nearly all of the best trained and most effective units from the Interior Ministry. That is seen as weakening an existing force that could prevent a new KGB from misbehaving. Vladimir Putin has dominated the government since 1999 and it was never a secret that he was a former KGB officer who hired a lot of other former KGB officers to run the government. But now Putin wants to make the National Guard immune to FSB (the post-Soviet KGB) oversight. Another interesting aspect of the National Guard is that the many para-military groups formed by the pro-Putin government of Chechnya are now considered part of the National Guard. A growing number of Russians are calling the National Guard “Putin’s Private Army.”
The army would be better equipped than the National Guard on average. But if the army did not revolt en masse, the loyal Putin army plus elements of the army that remain loyal could win such a civil war. The remnants of the Interior Ministry troops might not matter in that scenario.
And the National Guard would be useful against civilians, of course. The army would likely be kept out of that and the Interior Ministry would probably tag along with the National Guard. And if the Interior Ministry didn't go along with suppressing the people (perhaps in a more passive guard dury role), the army might take care of that.
Both scenarios assume the National Guard really does remain loyal to Putin. Keeping the leadership with Putin is the key, of course.
I wonder about the assumption of the internal nature of the Russian National Guard.
I worry that it would be very useful as a loyal army that could be used to attack a weak target nation if the army balks. But if the National Guard starts a war, the army would feel compelled by patriotism to join in defending Russia.
I also worry that the immunity of National Guard leaders if they order their troops to fire on civilians is very useful in a conquest of someplace abroad--like Belarus in particular, but also Baltic states in NATO.
As I've said many times, it is hard to hide what you are doing from foreign prying eyes. But you can lead foreign prying eyes to answer the "why are they doing this?" in such a way that what they see seems harmless to foreigners.
So I'm just saying that it is far more comforting to foreign prying eyes to believe the National Guard is intended to protect a fearful Putin from hostile domestic enemies; rather than as a tool to fight a war abroad and pacify the conquered population.
And even a fearful Putin might find a short and glorious war of conquest is just the thing to shore up domestic support.
What does Putin see as his National Guard's main role?