Hey, I understand the breed, having a rescue in my house. When he first came to us, he wouldn't trust my husband at all. It took us 6 months of hard work to get him to go to DH for a treat.
I know how to re-train dogs, and also know how to "read" them. Poor DH didn't grow up with dogs, so just didn't have the proper "senses" about how to read them.
Anyway, after 2 years, DH finally figured out that when our "rescue" wanted to go out and protect us from "dem da#m hawks, that he had to position himself in a certain way at the door not to get a bruising nip on the leg...
It is all in the body language between you and the dog... ya have to be a team, and read each other properly... Anyway, if you have small children, who are apt to scream and run, a rescue Belgian probably isn't a good idea. The ones worth rescueing have a strong prey drive, and that isn't a good mix with li'l kids, unless you are very dog experienced.
These are not laid-back retriever type dogs... But, since I live in potential "looter" territory, I get the benefits of dogs who lick and love me the way labs do, but who would take a bullet for me any day... They give me time to get the rifle from the closet, as they really know how to do the "tag-team" thing.
Once when I went out on the patio, late at night, they gave me a good demonstration of that technique, and chased off a hungry coyote. They were poetry in motion, believe me. The guy did the "agressive" routine, the bitch stayed close to me, but had her back hair up, gave all the guttural sounds, but only left my side when the guy told her it was "time to intimidate" the rest of the lurking pack...
Someday I'll probably live up in the mountains with plenty of space, then I may do what I've always wanted to...get a wolf hybrid. But not here in the 'burbs.