Julie,
we do collages all the time and I agree, sometimes it's the only way to get them all together. A few years ago, we had somebody ask us to shoot 7 Tollers for a family shot. And I agreed

.
We actually got 3 that were usable as is but we decided that for 2 of the dogs, we'd substitute heads from the other images. But we actually got them to pose and react for 6 frames. Incredible.
For my Rotties, I'd like to see the dynamic of having them all together. Annie is the dominant bitch at 11 years of age and Rowdy the 10-year-old alpha male. But I walk Rowdy and Sundance (the kid) together and Cassidy gets along with Annie pretty well. So I think we can pull this one off.
It would be easy to just set them up in the studio against a low-key background and then put them together later. But I like the challenge of getting them all in an actual shoot. Clearly, I'm into self-inflicted pain

. We'll see.
I love your collages. Simple and elegant. Nicely done.
Jim