As usual, spot on Krieghund.
second: do players retain the supply tokens given by turn even if they don’t use all of them?
I would just add as to the supply tokens that these don’t have to be moved onto the board as they are added per turn. for example, as the Axis, you get 9 I believe, and if you only wanted to move 6 of them onboard with trucks, the others would be left off board and could be moved on during your next turn, much the same way that not all of your reinforcements have to move on-board, but could be left off-board. they still would move on in the order from the chart though.