No, it's actually a wonderful pairing!
I have a male GSD and his 3 best friends are all Dobermans! 2 males and a female, he gets along great with all of them. They all play rough together but they can all handle it because they are the same size and are both powerful breeds.
I actually think they are PERFECT together.
My boyfriend is getting a Doberman puppy this year, I can't wait to see them all play together in the yard!
Sinister "The Prince of Darkness" 4 yr old black male GSD 3.11.09
Draco "Dakota's Unbreakable Vow" 6 mth old male Dalmatian 6.30.13
Cats: Chaos, Mayhem, Monster, Wicked