I have two manual focus bodies, and two autofocus bodies, and a shelf full och bodies needing repair... (ebay bargains that have minor problems).
I use one manual focus body and one autofocs body at a time, and keep/carry (dep. on the situation) the two others as spares.
So in your case, if it was me, I'd use only one body at a time, one for black and one for color, and keep the other two as spares, wrapped in a plastic bag, no batteries in, etc. And the olympus is a good pocket/backup camera to always carry (I have a 35mm mju too).
There's nothing more annoying than a failing camera body in the wrong situation.