Horses for courses

Horses for courses - it is important to choose suitable people for particular activities because everyone has different skills.

Example -  Ah well, horses for courses. Just because a plumber can mend your washing machine, it doesn't follow that he can mend your car as well.

Image - http://gakumix.com/blog/wp-content/uploads/2012/09/Screen-Shot-2012-09-26-at-12.01.37-PM.png