For some examples...
The O's #5 was Adam Eaton before they released him this week. His ERA was 8.56
The Sox #5 is Brad Penny. His ERA is 5.96
The Rays #5 is Jeff Niemann. His ERA is 4.53.
The Jays really dont have a #5, as they have 6 pitchers outside of Richmond, Halladay, Litsch, and Tallet who have made starts in the #5 hole (or replacing Litsch)
The White Sox #5 is Colon, and his ERA is 4.23, but has a 1.59WHIP
The Guardians have used Laffey, Sowers, Huff and Lewis in the #5 hole, and their composite ERA is in the 7 range
The Royals #5 is a Ponson, Hochevar split, and their ERAs are 6.49 and 10.80 respectively
The Tigers #5 slot is split between Miner and Willis, and while their composite ERA is in the low 4s, their WHIP combined is 1.65.
Glen Perkins is the #5 in Minny and his ERA is 5.35.
The Angels #5 is Shane Loux and his 5.40 ERA
The A's #5 was Dana Eveland and his 7.40ERA
The Mariners #5 is Jakubauskas and his 6.45ERA
The composite ERA for the Rangers #5's is 5.24.
As you can see, Hughes' ERA beats most of them, and if his ERA doesnt, his WHIP does.