I'll repeat myself one more time, because (with all due respect) now you're just talking in circles.
The discussion was about why areas in this subforum (but now you're trying to move the goal post by comparing some place like Oklahoma) outside of MI see severe weather more frequently.
The answer is because:
1. They live in an area where don't have to deal with the stabilizing effects from cool bodies of water, thus t'storm downdrafts have a much easier time mixing down to the surface to produce damage and a t'storm's updraft doesn't get cut off as easily.
2. They live in an area where the moisture content that contributes to the levels of instability/precip-loading is notably higher due to having an extensive coverage of corn fields, which empirically hold/transpire water much more efficiently than other vegetation. T'storms, by their nature, tend to develop more easily and propagate towards regions where the combined instability/moisture levels are highest.
It has little to do with droughts, pressure bars, frontal timing (which is mainly just bad luck), nor whatever other theory has been concocted.
Also, I'm not sure what's your point about Spring vs. Summer convection. The ingredients required for convection and severe weather are the same regardles of the time of year and location. It's just that in some places and during some seasons, these ingredients come together more frequently than others.
I can't make it any clearer than I already have. And if the answer (despite being reality, which you know good & well it is if you're a Met) isn't satisfying, that's too bad. My suggestion is if you're frustrated with severe weather climo in Michigan, you should move to a favorable region like I did.