The effectiveness of the armour entirely depends on how many Javelins Ukraine have left in my opinion. These were causing the bulk of Russian losses. The way this has been dragged on and delayed and delayed and delayed could imply that the Russians have been aiming to deplete the supplies and munitions that the Ukrainians have in order to make an offensive viable. The west doesn’t really have much left of this shit to give them either without taking it literally out of the hands of active units. Western manufacturing is not keeping up with the rate at which things are getting used.
I’m not ruling out that their offensive will go as badly as the Ukrainian one. It really depends on what they have left, how many weapons supply dumps the Russians have been managing to destroy with those regular missile attacks, etc etc.