I'm currently watching Heathcliff for the first time since I was little and it hit me fast how one of the cats sounds like Lurky and in one episode a genie sounds like Murky. Did both shows share some of the same voice actors?

I wouldn't doubt it. A lot of same voice actors worked on RB, My Little Pony, Transformers and tons of others.

You can also look online on many voice acting databases and see if they did do any voices