He cites more or less random numbers. However, there is a method. As I see it, the US may obtain ROU assets from Russia in exchange for a share of Ukrainian mineral wealth that is currently unreachable to Kiev (4 partially annexed provinces).

After this, US may get their brokerage, say, 50 % or even 75 % (which will depend of avarice, stupidity, and hauteur of Zelensky), while the rest may be placed into the fund created specially for the rehabilitation of Ukraine, under the most strict control directly from Trump-Vance-Musk's administration. Of course, any compradors, aiders and abettors of Biden-Blinken's dirty tricks during ten plus years of their pet business project and, specifically, three years during which conveyor belt of Ukraine aid was working incessantly, should be sanctioned, investigated, audited, and jailed.

Overall, Trump’s plan seems the best possible tool of excluding further flameouts of the conflict.