The Russians want ALL the reserves across those bridges before they’re taken out. That is the way they are fighting this, baiting the Ukes into committing everything, then destroying everything.
Russia won’t disable the Uke nuclear power plants. Part of this stop and start electric generation campaign has been to document the grid and how the Ukes utilize it transferring electricity. I think we are days away from Ukraine going dark and bridge less.
I wouldn’t be targeting the bridges leading to the front. I’d be hitting the ones between Kiev and the Polish border.