if the external modules can output arpeggios via midi then yes - all the mutant brain does is convert midi to cv & gates
you will probably find you want/need to use a midi merge box of some sort so that the outputs from both external boxes can be combined before being sent to the midi -> cv inteface
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities