Tiberi has a district. Stivers and Gibbs are combined.
You have to eliminate a Republican in any case.
Columbus has been split for years; I would say keep it that way. While it is growing and Dems have increased their chance of winning 1 (or 2 if it is split) seat, I would not hand them a victory like that unless I really had to.
The 12th and 15th, as they are currently configured, number 756K and almost 682K. An exchange of about 35K would make them ideal size. Tiberi won 56-41 and Stivers won 54-41. Yes, it was a good Republican year and at another time, the results would not have been so good.
Also I’m sure Dems themselves would prefer to keep one of their current incumbents.