Having two dogs raises one problem: how do you handle both dogs when you walk them?
Option 1: Two separate leashes
The two leashes are not connected to each other.
Good: The leashes cannot get tangled. Bad: The dogs can run in separate directions, you'll be torn apart.
Option 2: Second leash connected to the hand strap
You use one hand strap and connect the second leash to it.
Good: You only have to use one hand and you'll not be torn apart. Bad: They'll wrap you by running around you in different directions.
Option 3: Second leash connected to the hand strap and threaded in the middle
Connect one leash to the other and thread it in the middle.
Good: Better than option 2 since they have no chance of wrapping you anymore. Bad: Very heavy, like all 2-leash versions.
Option 4: Connect a harness strap to a leash
Use a harness strap to connect the dogs to the leash.
Good: Better than option 3 since you only have to carry one leash and the light-weight harness strap. Bad: The leash gets even longer, the dogs may step on it and become entangled.
Option 5: Connect the harness strap to the leading dog
The harness strap is connected to the leash, the leash is only connected to the collar.
Good: No risk of entangling. Bad: ...nothing?
But of course, this is still their favorite way of straying: Without any leash at all...