I guess it depends on what you mean by "better grasp of the tune."

I do play some tunes on two different instruments.

My personal opinion is that it is a waste of time to try to duplicate a tune arrangement for one instrument on another instrument.

E.g., if you try to duplicate a fiddle tune note for note on a guitar, why not just play the tune on a fiddle?

However, I find that it can be fun to work out appropriate arrangements of the same tune on different instruments, but I wouldn't use the terms "better grasp of the tune" to describe the rewards of the process.

And sometimes it doesn't work at all. I cannot come up with an arrangement that, to my ear, works.