I find this question interesting. Bulldogs certainly come in all sizes and not all breeding is done to uphold standards developed by national kennel clubs. I made a quick comparison between English bulldog standards issued by national kennel clubs in the US, the UK, and Sweden. UK and Swedish standards both state 25 kilos for males (55 lbs) and 23 kilos for females (50 lbs). Interestingly enough, the American kennel club has lower weight as official standard: lbs 50 for males and lbs 40 for females. That surprised me as my impression is that there are many much bigger bulldogs in the US. If that has to do with some specific breeding strategies or if a larger amount of bulldogs are being bred without the aim of fitting into the national standards, I don't know.
Even if parents fulfil national standards, it's no guarantee their pups will. Castor has quite a good pedigree but still ended up "too small" - at 6 years he is lbs 44. We took him to a big national puppy show when he was 9 months old and he received an honourable mention for his looks (!) but the judge said "although he looks good he is small and most likely, he won't reach the standard" which basically meant there was no use entering him in further shows. For other reasons, he has not entered any other shows, but clearly, size was an important assessment criterion.
I would say that in Scandinavia, serious dog buyers look for dogs which follow breed standards. That has not only to do with size, of course, but with the health benefits that come from certain lineages. That's also why there is so much work going on among serious bulldog breeders to help the breed develop in a healthy way.
I know [MENTION=3354]RiiSi[/MENTION] knows a lot about this so she can hopefully give an expert answer!