Well, to be honest I love the idea of it, because is realistic for any type canine to tuck their tail under, showing submission and like you said, scared.
Same goes with trotting... I think. Both felines and canines do so. But of course, I don't know much.
The only problem is. It could take months to do, atleast one movement aninamtion for a game. However, I'm not very well experienced to know, how long it takes.
Solvic <3.