The "rule of odds" suggests that an odd number of subjects in an image is more interesting than an even number. Thus if you have more than 1 subject in your picture, the suggestion is to choose an arrangement with at least three subjects.
So instead of an even number.
Its better to have an odd number of subject in your image.
Just a quick reminder to you all that besides the rule of thirds, it's also good to keep this rule in mind when you're out there shooting. Just see what you can come up with, how you can incorporate this in your images and find what works best for your style.