Might be interesting to compile a list of people who've held both Senate seats from a state. In addition to McSally John Kyl also did. Any other examples aside from the aforementioned Kent Conrad?
Barry Goldwater. He retired from Arizona's Class I seat after two terms for his presidential run in 1964, then four years later he was elected to the Class III seat to replace the retiring Carl Hayden and held it for three more terms.
David I. Walsh in the early twentieth century too. He lost reelection after one term in Massachusetts's Class II seat in 1924 only to win the Class I seat via special election two years later. He then held that seat for twenty more years before getting blanched in the 1946 midterms--by
another former Class II seat Senator, Henry Cabot Lodge Jr., who'd resigned three years prior to fight in World War II.
I imagine this was also at least an occasional occurrence pre-Seventeenth Amendment when state governments could rotate Senators in and out more or less at will according to the state's domestic political contingencies.
