It’s not a very good trick. Unless I missed something, the Ukrainian Army has never attacked Russia on its own soil aside from firing missiles and/or shells at a few military depots just outside the border; otherwise it’s been purely about defense or reclaiming occupied territory. If they manage to do that, then that’s when the aid would dry up and exactly how are they going to conquer Russia with what they have left?
It would also require Ukraine’s attempt to join the EU to be a sham since the EU really doesn’t go for conquest.
Or if you’re saying that losing the war will cause Putin to be assassinated (which might happen) and what remains of the Russian government will then pick Zelenskyy as Putin’s successor? Because ha ha ha no.
Also Zelenskyy was born in Ukraine. He was technically born as a Soviet citizen, not Russian.
[Edit] I later did a quick check on his parents. His father worked for a Soviet mining company based out of Russia at one point, but he, too, was born in Ukraine. Wasn’t able to find much about his mother.