You should really listen to the local vet. Vaccines are one area where little to no money is made so you don't need to worry about them just trying to turn a buck on you. They will have the best idea of what diseases are seen in the area and what is needed to be preventative. I know it seems like a lot of vaccines but these are the reasons that things like west nile are on the decline. Waiting to vaccinate until you see problems (ie birds or other animals getting sick) is too late to prevent transmission.
The reason there are so many vaccines these days are because there are so many diseases. People didn't used to fly all over the world and bring disease back with them, now a days horses, people, dogs, you name it are all jet setting around bringing god knows what with them. Thank goodness we have vaccines to protect us against some of the worst offenders!!