I don't really think those songs sound anything alike. I purposely chose songs that sound nothing alike to be satirical since this topic has me comparing every song now and that's kind of missing the point of the music. He's one guy and he's got a certain style and only so many stories to tell. But anyway, you probably knew that DMD3.
On the topic of songs running into each other in your head, All The Lovely Ladies and The Pony Man seem to run together in a funny way: All the lovely ladies in their finery tonight, some are white and some are brown.