There were 6,700 + hospital admissions for dog bites in 2014 according to the NHS:
httpwww.nhs.uk/news/2014/04April/Pages/Dog-bite-hospitalisations-highest-in-deprived-areas.aspx
Presumably most people are not ok with their child losing a finger or having facial scaring requiring years of reconstructive surgery, as long as the danger of actual death is low 
Those are obviously only the attacks reported - most people try to avoid going to hospital when their own dog or that of a close family member or friend has bitten them due to the risk the owner will be "in trouble" or the dog removed... and of course many attacks are painful and unpleasant and have lasting effects but don't require hospital admission.
Comparing human on human attacks to dog on human is odd imo - the comparison should be human on human to dog on dog - and there are countless dog on dog attacks in public daily (which people put themselves at risk splitting up).
Responsible dog owners are fine, some dogs are lovely, but people trying to argue that it's vanishingly rare a child will be bitten by a dog are simply delusional.
Nobody has to get used to being in a confined space (ie indoors) with any dog - it is not in any way comparable to crossing the road because it is an easy situation to avoid.
People get irate about all sorts of vanishingly tiny perceived risks and are very sanctimonious about taking risks which never or rarely result in fatalities in the UK, yet so many have this enormous blind spot about dogs and make a point of pride about clamouring to put their children in the way of unknown dogs - it's baffling.
The size of the dogs isn't particularly relevant I agree - labradors are one of the dogs most likely to be the biter responsible for personal injury claims I read somewhere, and they have a wonderful reputation, it's just that there are so very many of them... Any dog can bite though, no matter how fluffy or beautiful or loved...
I must admit I think the OP's dogs and family sound somewhat fantastical far too unique to have posted about in so much detail given there are apparently only 600 Otterhounds in the UK a family with one of those, combined with the fairly unusual other dogs and the two sets of twins under 10 would be very, very, very recognisable indeed...