You said the doc is best in city you are damn right.Generally most vets would would neuter and then ask.There are 2 aspects why neutering has to be atleast after one year.Firstly testicles do produce hormones,
which are necessory for proper physical as well as mental growth.These hormones are very complex chemicals and not just testastrorone.Without them at young age,the dog growth is skewed,even if he may
appear to be physically growing well.Simple harmless example is your dog will never lift his leg to piss.
Second reason is,there is hardly any connection between teenage hyperactvity and neutering.Only the surgical pain and stitches may put the dog into less active state.Some dogs will return to their tantrums
some may not be that quick.Meanwhile the age catches on and dog becomes sober.Right result for wrong ,expensive and painful reason.Females too can be equally active and destructive.Now here is the
punchline.The quality life for labs in today's urban life is 2 to 2.5 years,after that anyway he is going to be fat couch potato with one walk around the apartment park if boss is home early and if it is not raining,and if there are no visitors and owners are not going for evening shopping or party and....Somebody said labs are great swimmers ,can retrieve nets,ducks fallen in lake..Point is let your dog have some fun while he can.Believe me there are breeds and breeds which make worst lab seem like Buddha.Yet people love those
breeds for their energy.A duschhound,an airdale or central asian sheepdog or one macaw bird can be more than 5 labs on rampage.
Early neutering is only for retained testicle which fails to descend to scrotum even after 8 months and treatment.There is real risk of cancer then.