Wouldn't it be a good start if the numbers that are shown in the tiles did not represent the TUs that are spent, but instead the TUs that remain after giving the move order? I find myself subtracting the TUs-to-spend from the available TUs all the time, as the latter value is of more importance. Showing remaining TUs in the tiles directly would save me from a lot of math
You could also add little icons to that number, showing what other actions / shots are still possible after giving the move command. It's all math -- and math is what computers were made for in first place.
