Yes...do it the way DIKI said.
I have a lot of experience in this area...and to be honest don't expect to have full control of arranger X from arranger Y.
It ain't gonna happen...
But a top notch MIDI second lower KB, with multi zones and 2 MIDI outs..well you can do a lot.
You will have to send some serious time to get it all working.
Maybe add a Korg Nano control too.
Also, to get the most cntrol...you may need to add a PC. (Oh No!)