I will say that it can be an advantage, but it's rare. It becomes an advantage when your primary language lacks the tools to do something well. One of my previous companies was a PHP shop and they used Python to chop up audio files, which would have been very cumbersome to do in PHP (few if any existing libraries). My current company implemented complex data pipelines in PHP, which really should have been done in a different language (python or scala would have been natural choices).