Revisited topic:
I tend to wonder on this day to day. How much our household would change with another to keep Ragnar company.
So for those that have two:
1. Do you shut down all rough housing inside- only allow it outside?
2. How do you manage this? Put them both in respected corners when they act up?
3. What are your house rules for having two beast and how do you enforce?
4. What else am I forgetting that needs to be addressed?
Well, I am new here and am learning from this forum that not all dobies are alike! But we have had three large dogs (and three tough cats!) at once for a very long time and, granted, while not all dobermans, all are in the 80 lb+ territory. We also have a house-full of kids and I'll out myself now as the weird longtime homeschooler (not crisis pandemic homeschooler) \ living on a hobby farm, so we might not fit the typical mold. We are home a lot and we have lots of room for plenty of critters of all varieties, so take our experience with a grain of salt.
Our oldest girl, who is now 11.5, is the matriarch and rules the roost accordingly. She has never put up with shenanigans from the other two, or the cats, or the kids. We actually call her "The Fun Police". But I give her complete credit for the other two dogs turning out as well as they did as we got oldest and our recently departed dobie one year apart. Then Dog #3 we got 2 years after that. Oldest ruled with an iron....paw? (She takes her role so seriously that I do put her away in a bedroom when other kids come over to play. She is NOT a fan of screaming and chasing be it human or canine.)
1) They never really tried to rough house much indoors- they would do what I called floor fighting, or the lazy mouthing like in one of the previous pictures. But even for barking at incoming people/critters, oldest dog would go after any of the other dogs and making sure they played Chorus and not main role.
2) We did have crates for everyone when they were all young and not quite trustworthy, but they all dropped off needing them by age 3-ish. But again, oldest kept the order for the most part. And we were lucky that the younger two were really laid back, submissive type dogs. A stern word pretty much cut anything out indoors- but like I said, maybe we have been lucky with a sedate doberman (minus the whining?!)
3) House rules I guess would be off carpeted areas (kids rooms) and no dogs on beds- baby gates and we never let them on a bed. We fed them in order of age/dominance. Also, no chasing our cats. We have an insane number of dog beds scattered throughout the house to help save the furniture. They are just as happy on plushy dog beds its seemed. The cats have ironically been the main furniture destroyers. Way easier to replace $30 Sam's dog beds than leather couches. Wish cats would get on the same page!
4) The biggest caution/awareness I would have with multiple large dogs is meds and vet cost. As they get older, there are a lot of meds that start adding up. My husband and I have a "don't ask, don't tell" policy when it comes to animal cost. He is all about happy wife, happy life, and isn't as "interventionist" as I am (even though I'm not extreme), but knows they are a huge part of my heart so this is our happy marriage agreement...... So I just take them to the vet, pay the bill and we don't talk about it!

But wow, sometimes it is shockingly expensive. More labs/tests with age, and of course more meds. Just heart worm, flea med, vaccines and check ups is daunting- add in additional things and it can be- wow. Then senior panels, and other maintenance meds say for spay incontinence or otherwise, the bills can pile on.
Overall, I would say having an older, more mature dog to help keep a puppy in check is a huge blessing. So if I had a rambunctious dog as the oldest I *might* wait another year or two. I would think a rambunctious young dog might just make things worse, although it might also have the effect of maturing the oldest too. I am a "more dogs the better!" person though, so I probably shouldn't encourage. :d