Me and my friend both have a dog but when we go walking together our dogs dont get along, what can we do?

My dog is a small dachshund(weener dog) and carlas dog is a lab, we have tried to walk with them togehter but baloo the lab is playfull and flo the weener gets scared when baloo gets playful so they dont really like each other and flo doesnt like the attention from baloo, now we have decided to walk them everyday after school together and play with them because we are neighbours, how can we get them to be close and how can we get baloo to be less active and flo to be nicer to baloo?there is age difference between them becuase baloo is big and 7 months and flo is small and 4 years old. please help us we really want to walk our dogs together and let them play without trouble. I am scared that flo is going to get angry and bite baloo and they will get into a fight. what should we do?