Well I started following in 1957, and I know that Runnels and Vernon were long gone by then. I remember that nearly every team we played seem to have at least one great player where my dad would say "he used to be a Senator". Runnels and Vernon for sure, but also Jackie Jensen, Early Wynn, Bob Porterfield, Jim Busby. (And others that don't readily come to mind.)
Runnels was traded just after '57. I remember that trade all too well: Nats got Norm Zauchin from the Bosox. Zauchin hit 15 homers as the Nats 1B in 1958 (I had a full set of '59 baseball cards). Runnels hit .300 about five straight seasons in Boston.
Vernon was traded a year earlier, and hit about .310 at age 38 for Boston. The Nats got a bunch of players I don't remember except for Tex Clevenger.
Jensen was before my time, but my Dad always grumbled about that trade. Jensen was a basic 30 home run / .300 hitting LF, and I think the AL all-star voting usually had Jensen, Ted Willliams, Mickey Mantle, and Al Kaline in the OF. Sometimes Kaline started, sometimes Jensen. Ugh!
Busby was an elegant CF in Griffith Stadium, a park with the biggest CF in baseball...except maybe for old Yankee Stadium.
Calvin Griffith must have been dumping salary. No other explanation if you look at the Vernon, Runnels, and Yost trades. If would be interesting if someone wrote a book on the Calvin Griffith years in Washington, but nobody writes about teams that break the record for consecutive losses.