Runts don't always end up the smallest at the end, it's not a guarantee.
Many if not all of reputable breeders breed for the standard which includes size and don't have oversized dogs
Jasmine - Female Miniature Poodle - born Aug 15, 2010
Loker Delgado Von Stalworth - male GSD - born Jan 26, 2012
Koda & Zazu - 4 year old male cats