If Ukraine falls, then those corrupt officers or officials end up dead or in prison. And there families as well. Even if they are enemy collaborators, well, traitors aren't looked at kindly when their usefulness ends. Russia has enough kleptocrats of its own, they won't need to tolerate one's from Ukraine. The brutal nature of the Russian regime does put a lot of pressure on Ukraine.

You can see it on the battlefield. Ukraine fights so hard because they are facing genocide if they fail. Russia miscalculated how well Ukraine remembers the Holodomor. There might be some corruption left, but not nearly enough to siphon weapons and supplies from the front line.

Russia on the other hand, they face no consequences for failure. If someone's army looks below the money spent due to corruption, it's Putins army for sure.