If I had put a harness on my Malamute, she would have dragged me into the next county. It was in her blood!
She started with a choke chain and eventually a simple collar. She could carry a 15-20 lb load in a pack-vest with ease. Made her carry her own food, water, and snacks, on long outings. Along with some for me too.
With two exceptions, I’ve trained all my dogs to wear a ‘cargo’ vest. I’ve even got one MOLLE rig set up with canteens and AR magazine pouches.
lol. You and your dogs seem ready for long distance hikes.
Me and Rockwell just walk a mile each evening.