I was not correct, because I had MC's record wrong in that scenario...thanks for catching that. If Tyner, MC, and SC are in a 3-way tie, then something interesting happens that I hadn't thought of...
Since wins over teams that are not eligible for the TSSAA playoffs do not count, then we would have to discount Tyner's win over Faith Covenant, MC win over Taft, and SC win over East Lit.
SO...under the Boyd over Tyner and SC over MC scenario, the first tiebreaker would apply.
1. Boyd
2. SC -- 6 wins, head-to-head over MC
3. MC -- 6 wins
4. Tyner -- 5 wins
Actually, even if those games counted, this would still be the order.
I've corrected the first post to reflect the "non-eligible team" wins for the Tyner over Boyd & MC over SC scenario.