It could be one or the other or both. That's up to the dog. I did know a couple with two Great Danes, a male & female, and the male resource guarded the wife from the husband. It was escalating to a pretty bad point when they sought the help of a dog behaviorist. They came to some group classes that I was attending so I saw the progress they made. But a big powerful dog in charge of the humans tip-toeing around was something I never want to see again. That dog was not aggressive to dogs, just to other people getting near the wife.
You seem to be all aboard on being pro-active and preventive with Kylo, and I have faith that you can handle whatever he brings your way. The loving Dobe you see is 100% correct, these dogs are impossibly devoted to you. Most SSA is easily managed, especially if you don't live with another male dog in the house. I think you guys will be fine.
