How is it different? What is so different to your dogs with the two commands that they "may" make a bad choice with "down" but not with "stay"?
Over preparation for the unexpected and ... life with "Boxers."
But to your point ... most likely every dog will hold a "Down" if the owner is in sight?? And a three minute out of site "Stay" is part of the CGC test I do belive??
Jeff Gellman says he no longer teaches a "Stay" as a separate command. He also has a partner and she says ... she has to crate her "Mal" to take a shower, becasue while her other dog will hold Place with her out of sight ... her Mal she has to crate??
Since they are partners ... most likely neither of them train "Stay??"
I don't know but I do know if I am in sight and I told my dog Down ... they will down. But for how long ... I don't know?? I've never put a dog in a down for more than 3 minutes???
And I'm eyes on then so if they moved ... I could repeat "Down" but I will say instead "Stay" and they don't move (get back up). If I have them in Down or Place and I'm out of sight?? I give two commands, "Place and Stay" they might break one but they won't break two.
I want my dogs to understand "Stay" as a separate command. I can shout "Stay" ... louder and faster than I can a dog's name. And they respond ... instantly ... then I can call them back or add Down if required???
I typically practice "Down and Stay" together ... but I train Down and Stay at random. As we walk about or play, I'll issue either or both commands at random and if it's "Stay??" The dog stops moving or if it's Down the dog goes Down and I'll say or repeat Stay if required???
Sure it's redundant but if ... I don't have eyes on a dog ... I add "Stay" ... to my way of thinking they may break "Down" if out of site but they won't break "Stay??
Well Rocky did twice and I started to add "Place/Stay" with him if I'm out of sight ... the second time he broke and out of sight "Place/Stay" I was glad he did ... toddler issue!
So ... that' all (my) theory but in the real world ... I don't go looking for trouble but if it comes "our way" we're ready to deal. If ... sigh, when we get charged by loose dogs. I'm not telling my dogs Down?? I will tell them "Stay" and that's what they will do. Rocky proved that was a sound tactic (yet again) on our last recent and now "Walking Stick" equipped loose dog encounter.
I was slightly out of postion (Rocky was behind me off leash) and he was locked and loaded this time as we were charged. I had no time to get in front of Rocky he was beside me ... not ideal. If that (non pointy eared lab got by me) it was gonna be bad! I told Rocky, "Stay" as the dog charged and he did and I stopped that dog. Then I repeated "Stay" again, to keep Rocky out of that now, Dog and Owners face! And he did just that ... Rocky did not step one foot forward. I'm not going to put my dogs in a "Down" in a loose dogs gone wild situation?? I will tell them "Stay" and I will deal with the situation. So for me ... "Stay" works out fine.