As Ed S, pointed out, Abilities display in the order they are made, newest being to the left. (IE: when you Add an ability, it shows up as the left-most button. By changing the order of the abilities on your Character Journal, they will match the order on the Token Action bar. The trick to remember is that you have to have moved them at least once. ie: If I just added an ability, I need to drag it between others and move it back down for it to properly show at the end of the list.