Okay, aggressive? Or assertive? I don't think it's ever a good idea to have an aggressive pet because you never know who it will take out that aggression on and physically harm.
My geese are assertive, in that they will defend themselves with hissing and charging if they feel threatened. They will "yell" at chickens who try to take their food or nesting spot, but if they cross the line and bite at another bird, I quickly redirect them.
Also, I don't want them to get aggressive with me. Sometimes, I have had to pick up a goose and once took a wing to the face that left bruising. She wasn't even trying to hurt me, she was scared and didn't want to be moved. The damage could have been much worse if she had been trying to harm me.
I don't worry about predators with them as much as with my smaller birds (chickens and runner ducks), but a stray dog can be just as deadly as a wild predator. My big-bodied girls can't fly very far, and they sure couldn't outrun a dog.
That's where I would be concerned with the Labrador. It's possible you might be able to condition and train him NOT to bother the geese, but separation is probably a better idea.
My geese have a small house, made of wood and wrapped in hardware cloth, that's inside a chain-link enclosure. But they spend most of their day outside the pen, keeping my feed costs down by eating grass.
There's plenty to consider before you get geese. I didn't do that first and had to learn a lot along the way.