I agree and admire your logical capability. Here, my point was just if both have the stop sign, the one entered the road first should have the right of the road, no matter whether it's straight or make turn. At least this is what I learned in Indiana.
I took back any unsolid statements, and hopefully the OP could find a good way to go through this, and be careful when driving. (I remember one tip in Indiana driver regulation is that the driver should always watch the situation around your car, which also benifits me most.)
Best,
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