i think temperament (sp) is kinda what you make it. don't teach it to be mean...just alert. a well timed growl, can have you moving to a gun in no time. you know? i've had a rotti-doberman mix before, and she was the most playful dog you could find. she didn't know how big she was either. 140 lb "lap dog" comes to mind. we currently have two boxers. one is just learning how to "guard the house" and the other knows how to hide behind the big one. they love my niece and nephew, and they know when enough is enough. a buddy of mine in the army had a full blood pit bull. named it OZ. dumber than a bag of hammers. but they also smoked it out multiple times before enlisting. that dog had presence. i had to house sit during a rainy time for them, and my instructions were to wipe his feet off before coming in the house. i did it once. the second time, he growled when i lifted his back foot
...down it went...and out i went
("stage right" style) . to hell with the carpet. if you know what i mean. additionally, he'd let the dog "play" with his worn out mud tires for a lifted Dodge 1500 crew cab...thingy (i don't know trucks too well). that dog could literally toss one across the yard, and not even worry about it.
so...i don't know if i helped or not...i'm no dog expert, but i know the dogs, and dog experiences, I'VE had. good luck.