Hi,
Then what ever your data source have fields which are going to cube, those objects need to add connected cube only. so don't split adding info object some to this cube and remaining to other cube.
based in your data source add related info objects to related cube.
if you have one dimension left, then add all relevant info objects to new dim, adjust ramainingg info objects in to 15 dim. at any cost you need adjust them in 16 dim only.
Your at dev system, so just add them and load the data check it. if you face any problems let us know.
Thanks