I have two, male and female.
The female is everybody’s friend.
The male is the house cop.
He maintains order but he does get along with everybody.
It really depends on the dog.
They don’t have a ‘pack nature’ like my Sight Hounds do so *can* be one-dog household critters or lovers of all creatures, great and small.
It’s extremely variable and every dog is different.
They generally do see themselves as Your Dog and can be a bit jealous of your other dogs but it’s not unmanageable.
Usually, the pack hierarchy sorts itself out *if* you let it.
I’ve had multiple male Dobes at a time with no problems and I know one breeder whose males all run together just fine, albeit with a very established pecking order.
At my dog park there's a regular visitor: a large red Doberman who patrols others and is thus known as "Officer Dobie." He breaks up skirmishes, not suffering pugnacious pooches gladly.