I'd say 95% of walks are staggered or there is one handler per dog if together since most walks are for training rather then exercise. For the 5% that are easy strolls or hikes I take both by myself without problems.
Jasmine - Female Miniature Poodle - born Aug 15, 2010
Loker Delgado Von Stalworth - Male GSD - born Jan 26, 2012
Koda & Zazu - 5 year old male cats
Alex - Male Cocker Spaniel (rescue) - RIP Cuddlebug 2007-2010