Ukrainian tanks are not immune to the mud.
The routes the Russians - who are advancing! - will follow are easily know and can be prepared for. They can be blocked by those infantry: kill the tanks at the front and cause a massive traffic jam. That route cannot be advanced up until after the wrecks are cleared. Go off road and get stuck. The recovery vehicles have a problem getting to the wrecks due to the traffic jam and mud.
The mud makes the terrain more like a series of canyons rather than a flat plain. That mud makes infantry king on this field until the mud dries out.
Infantry can escape and not be pursued after firing an ATGM by tanks. Mud doesn't affect them as much. The Ukrainians have been handed a gobsmacking amount of ATGM. Sending helicopters after the infantry runs the risk of MANPADs...which the Ukrainians have a lot of, too.
When the mud dries, the Russians can get off the roads and cue the Doom music. Until then, the Ukrainians will have the advantage.
The Russians should know this. It boggles my mind why they did not wait until May or June to start the war.
