About the plan of may 1941: in a discussion with the Soviet historian Anfilow,Zhukov said :it is very good that Stalin refused the proposal,because the situation of the Red Army would have caused a catastrophe : Source:Besymanski :Stalin and Hitler P 443 (cited in geschichtsforum de. er Shukow-Wassilewsky plan von mai 1941 post 120
Both of your expansions/explanations/clarifications seem quite plausible and not at all mutually exclusive. Thanks for the additional information.
Also you cant really call it a plan, since no staff work was actually done. It was a proposal. To define a plan it means that units are assigned an objective, given routes to march, timelines are made, resupply points and a lot of specific details are worked out. There are no such plans in the archives.