the only way I know to split stuff is hit edit layer once in the base map for map types. Then delete either what you want to change or what stays the same so only the other portion is left on the map. File - SAVE AS and save as new layer with correct hybrid. 

Then close that editor and the main map. Start over and do it again, but delete the other portion and then you can save or SAVE AS and pick right hybrid if needed. Then you will have half and half split or whatever it is with the correct products and complete map and correct acres