Just a thought...
We could do one picture as the whole background and then do other pics inset, as Andrew suggested.
Looking at the photos now (I know we'll get more in, but go with it) there are a few water photos. Chose one as the background and then all of the other water photos could be inset.
There are some action/agility shots, take one as the background and do others of the same inset.
We can do one of smiles.. one of goofy faces.. one of sleepy pics/faces.. the options are nearly endless.