Are you thinking three full body mounts? Or three tail fan mounts? There was a guy on here that had a triple tail fan mount a year or so back with wings that was nothing short of amazing.
For full body mounts, if you're wanting to incorporate them all together, it would be tough for me to decide between live poses, or the dead mounts.(As opposed to three individual mounts, you could really get a verity of poses for stand alone appreciation) I think for a dead mount, the two toms on the outside with the jake in the middle strung between two old fence posts would look amazing. It would fit flush to a wall good, but take up a lot of space.
If I was to choose a live pose I think the two Tommy's about to lay a beat down on the jake with one of them spurs up even would be totally badass. This sort of mount would likely require a very large custom pedestal for the mount or be placed on a large dresser of some sort.