I don't know that "simple" is a word one would use to describe a junk rig, which is basically a complex balanced lug with full length battens and system of multiple sheets rigged up the leech--not the sort of thing which lends itself to being knocked down and stowed out of the way for rowing.  A dipping lug, or a pair of them as a cat-ketch or pirogue, would be more typical of long, lean, multi-oared rowing boats, the idea being to set the sail(s) once a course can be laid, with maneuvering to be done under oars with the sail rig stowed.

Once you start attempting to turn a good rowing boat into a sailboat, the necessary changes will make it a worse rowboat.  Happy compromises are rare.  I used to have a Sea Pearl 21, basically a lengthening of LHF's Carpenter design (a rowing boat for 1-3 rowers with auxiliary sal) rigged with a much more substantial cat ketch rig and increased beam just short of completely ruining her as a rowboat.  She was a pretty good sailboat in skilled hands, with rowing as a passable option for auxiliary power, if I practiced it enough to stay in shape and keep up my technique.

Just thinking out loud, here....

.....Michael