Molossers don't combine prey and defense like the traditional SCH breeds. Molosses don't unload into prey. For sleeve biting you work them in prey only. If you were to work them in defense they wouldn't hold the sleeve. SCH is definitely not for mollossers. Not for bull breeds either. There may be rare exceptions. Working with molossers in SCH is purely for fun and/or showcasing your training skills and your dog. The core of real old school SCH training is all about the dogs combining prey and defense in a powerful way. I've never seen a molosser do that.