I've had my own life experiences with dogs and walking dogs that pull and dogs that are good on a lead.. I also have experience of a dog that hated strangers and was very aggressive to towards them 2 weeks into training her myself and shes letting people stroke her but shes still needing constant training still. I have a 2 year old morkie/Jack Russel that I walk daily. I can handle upto 3 well trained dogs together if they all like other dog and for dogs that dont like other dogs or aren't great on a lead then I will walk them alone. The first walk with me is free.