Splitting Movement and Power Tokens
Yes, this is allowed. From page 13 in the rulebook:


  If marching units enter an area containing one or more enemy units, a combat ensues (only one combat, however, may be initiated for each March Order).


So there's only a problem if you try to initiate two battles with the same marching order (which you're not permitted to do. But as described on page 24 in the rulebook:


  A Power token on the game board is returned to the Power Pool only after an opponent takes control of its area. Marching into an area containing only an opponent’s Power token (i.e., no enemy units are present) does not result in combat, and the Power token is simply discarded to the Power Pool.


No combat occurs in this instance, therefore it is an allowed action.