More training. lol. Individually. How much training have they had?
It's certainly possible to walk 3 dogs peacefully. I do it often when I am at my dads house as we have a pack of 3 over there (including Jackson). A little more difficult, definitely. Makes for more work but it CAN be done. We do have one dog who is a barker and leash reactive to other dogs and are working on it.
Jackson goes for walks about 5 days a week - generally about 2 miles each day. Sometimes around 4 miles. I am a dogwalker so am lucky enough to have 3 clients who he gets along with and so he gets to come with me. I've walked him together with Husky's, Rottweilers, Labs, and Pit Bulls. lol (not all at once of course! Ha ha).
Good luck
