The proper way to do it: attacking general maneuver overcomes defending general maneuver and terrain penalties.Unless they're adding some other benefit, the only benefit after these changes is the increase in speed a high Manouver General can give. This could be useful in it's own right, but maybe not as useful as they were.
6 maneuver general attacking 3 maneuver general in mountains, across river = 0 penalty.
Even better, if your pips are better, the defender gets the penalty!