There is a theory, or if not I can make one up, that speakers who are fluent in more than one language tend to mix, match, and meld, not only single words but also the elements and ideas found in all the languages stored in their brains. Here are some examples of what I mean:

In Irish the word gorm means blue. In an Odin tale, Odin names the best of everything. This takes quite a long time, because this naming is a form of bragging, and Odin owns the best of everything and wants everyone to know it. Just ask him. When he gets to the subject of dogs, he names his dog Garm as the best dog ever. Obviously, gorm and Garm sound a lot alike.

It is an old folk maxim that gives the name Old Blue as a proverbial dog name, just like Spot. Old Blue is a good name for a hunting dog, but rarely used for a poodle.

Those of us who live in the sticks have heard of a coon dog (Not corn dog).

In the book Arcade of Word Origins by John Ayto, page 287, some explanation is given about the origin of the word hound. "Until superseded around the 16th century by dog, hound was the main English word for dog (and indeed its relatives in the other Germanic languages remain, so German, Swedish, and Danish hund, for instance, and Dutch hond)... It goes back ultimately to Indo-European *kuntos, a derivative of the base which also produced Greek kuon do'..."
(Arcade of Word Origins, John Ayoto, Arcade Publishing, Little, Brown and Company, New York, 1990).

Of course, there's also the phrase hound dog, which is really dog dog, called a reduplication.

Here's another example: The Old English word for wise is horsc.
Horse, horsc is, therefore, Horse wise or horse sense.

A lot of these types of old phrases are really reduplications.

The brain seems to want to balance out both sides, but since the left brain and the right brain differ in function, just as in England long ago when there were Norman French words and Anglo-Saxon words for essentially the same thing, such as pig and pork, calling to mind the expression pig in a poke.

The brain seems to want to divvy out a slightly different form of a word to each hemisphere of the brain and then to come up with a new product in phrases as in the case of horse sense.

Unless you look up word origins, you probably won't know the Old English or the Old Irish words, but people like these combinations, as evidenced by their use up until the present time.