So what? Did he say this is the plan he will be proposing? No. He just puts it to a vote, there's zero evidence he even proposed this to Ukrainian authority. The finer points of his plan doesn't matter one bit, since he won't be doing the negotiations anyway. If there is going to be a negotiated peace, it'll be done by diplomats and politicians, nobody is going to base the peace plan on his tweets. The entire point of the tweet is not debating the fine point of which territory belonging to whom, the point is to get people thinking about a negotiated peace instead of keep escalating the war. And in peace negotiations there is going to be compromises, Cuban Missile Crisis didn't end without US giving up something to the Soviet.Doesn't mean he got this one right, obviously. Nothing about his proposal was realistic in the least. It's pretty obvious the Ukrainians won't agree to it so it's a non starter, end of story.