Why would somebody without a military background want to play armchair general? Maybe because they have no military background!
Foolish though it be, here it goes: how should the Russians finish off Ukraine? Everybody expects them to feint at Kiev by coming south from Belarus. Then they expect the main Russian offensive to be in the south and east, say, on the Zaporozhe front or upriver, nearer the Donbass proper.
For that reason I think they should make Kiev the main target. If they can threaten to topple the regime, Ukraine will have to pull its troops back from the south and eastern front. Ukraine will not want to blow up the bridges across the Dnieper until it has pulled its troops back towards Kiev. Perhaps the Russians can get control of those bridges during this transition.
But can Russia decapitate or topple the Kiev regime without massive civilian casualties in Kiev, which is a huge city of a few million people?
You will tell me that my suggestion is totally amateurish and stupid. Is it any more stupid than launching a major offensive where everybody expects it?