I've had a look at the JHS mini tap and now believe that because this thing have 3 outputs you really don't need a spliitter. You just have to use one output for each H9. This way you don't even need any midi cable between the two H9.

Ths being said, I do believ that the BEST way to do what you want is to go with the MIDI way I've explained in my previous post. This will also allow you to add as many slaves as you want, keeping all of them in sync.

LA