These three breeds are all very different.
I run ddb rescue nation wide for the breed, and "doggylover" is completely wrong, ddb's are amazing family dogs, their "job" is to be part of the family. They must be taught respect for children and children must be taught respect for ALL dogs, your children must be above the dog in the pack. The majority are fabulous family pets. They can be dominant and stubborn, they can be dog aggressive (usually same sex aggression once they reach maturity), they may also have a high prey drive (meaning may chase small animals that run). The ddb is NOT necessarily a breed that children should take on a walk because they are powerful and even though they may be extremely well trained, you never know what other dogs may attempt, so it's best to just eliminate that issue and not allow children (under 16 or so) to walk them alone. They should NEVER be human aggressive but they will protect you if the need arises(thus another reason why children should always be supervised and children should be taught not to play fight with each other around any working breed, most will not tolerate play fighting, because of this, they are also NOT dog park dogs, they may not start any fights, but they will finish it if others are fighting/bickering!)
With the DDBSA Rescue, we match the dogue to the home. They are all thoroughly evaluated and vetted (spayed/neutered/micro chipped/vaccinated and any other medical issues taken care of). Some of the dogues in rescue are known to be good with children, a few are not good with kids. We also check refs on potential adopters and do home checks as well, getting to know our potential adopters so we make a good match for their family.
The Dogue de Bordeaux is a fabulous breed, but not a breed for everyone and especially not for a first time dog owner. The main reason we get them into rescue is once they hit maturity, they may become more dominant/same sex aggressive adn they may "push" the limits. Most people who turn dogues over to rescue had no idea what they may be getting because they purchased on impulse (pet store) or purchased from a back yard breeder who gave them no education on the breed what so ever. They purchased a cute little wrinkly pup not realizing it was going to get big, slobbery and shed, so they banish it to the yard where it becomes destructive and attempts to assert it's dominance, or it no longer gets along with it's other canine family members of the same sex even though it grew up with them.
Obedience training is a MUST for ANY working breed dog, especially the ddb. I recommend if you adopt a dogue, put it through at least 2 levels of structured obedience, you will learn more about the dog and vice versa and create a stronger bond with the dogue (actually, this goes for any dog you adopt) and you both will learn what to expect from each other.
Best of luck on your search for a new family member!!