The other consequence of splitting Tennessee would be that we would now have 51 states. How do you arrange the stars on the flag? 51 is divisible only by 3 and 17...you could treat it as 21 + 30 (just as the current 50 stars are treated as a combination of 20 + 30), but that still doesn't lead to a neat arrangement of stars.
There was a proposal in Congress during the Civil War to revert the rebellious states to territorial status, establishing a Territory of the South, after which the area would be carved into new states, with two states created in Appalachia while merging North and South Carolina. Fascinating!
Three rows of 9, alternated with three rows of 8:
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Or maybe something more creative:
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *Okay, I'll stop now...