Jack basically summed it all up for you. Maybe my two cents on top of what Jack wrote will help also.

Don't expect all pedigrees, or even most pedigrees to be true.
Don't try to base a breeding program around names on a piece of paper.
Don't expect dogs with the same ancesters in the background of their pedigrees but from different breeders to be the same.
All dogs have secrets and dirt in their pedigrees.

If you have good dogs male and female but from different sources or even crossed up, all is not lost. You can still build a family from them. I know becaused I did.

If they are good breed them.
Don't ad anything knew.
Raise and test all of their offspring.
Breed the good ones together and back to their parents.
If you don't get any good ones scrap the whole lot parents included and go buy some stock from a reputable seasoned breeder of quality bulldogs.
If some one is trying to sell you crossed up bulldogs keep shopping.