Why not just select one model, apply a boolean to the second model, then add another boolean modifier and add a third model, etc? I don't see a reason you can't add more than one boolean modifier. Either apply it to the first model then add another one, or select the second, third, etc., and add boolean to those as well. Cybermonk's solution is the most elegant and simple though. I'd go that route first.

______________________________________

My Store
My Free Models
My Video Tutorials
My CG Animations
Instagram: @luxxeon3d
Facebook: https://www.facebook.com/luxxeon