Hi beanie:
I was just about to go to bed when I noticed your post.
I really, really feel for you because you obviously love your doggies to bits, as I do mine, and the toughest thing to do is to think that we could be nasty to them by putting them in their place, so to speak.
But, no, I don't think it's ever too late, but as I say it's hard being hard on them, if you follow me, and I sometimes think "Oh, God, they won't want to know me for having shouted at them so loudly." The next think I know, one or other of them's rolling on its back at my feet looking for a tickle!
I'm no expert at this, believe me, but maybe I'm lucky and have found something which works for me, but it's the only way, albeit far from perfect, I know to try to keep order!
It would be great to hear how you're getting on sometime later, perhaps?
In the meantime, they'll still love and worship the ground you walk upon no matter how much you raise your voice to them. Might wake the neighbours up as well !!
Best of luck. And so to bed !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!