I would still be interested in the 2nd way? 

The first option you described has the disadvantage that both H9s must use the same midi channel. Controlling the active state of both H9s separately is not easy to do AFAIKT.

also the program changes should be done in the 2nd H9 in a receive map which is not as flexible as using the Musicomlab to control specific combinations which is fixed with the mapping on the H9