I don't know if it's as common in the English world, but in the French dubs of series from the 1970s and 1980s, there are a lot of characters that share the same voice actor, if not literally the same voice! Among them are Astro, Sapphire and Kimba's daughter in the second series of KTWL.
While watching Bander Book, fafner and I recognized, among others, a few smurfs and Dalton brothers (from Lucky Luke).
Aside from one character, all the voices were done by well-known voice actors.
It's usually funny, and I think the voices are good, but it can be slightly annoying at time: since then, I got another series and there's one character in it that whenever I hear it, I can't help it, all I can think of is "Gargamel"! :d oh: