Seems very excessive to me! Why don't you have a titer done after the second set of shots...usually it's done 10 days after the shot. This will let you know if there is proper immunity levels.
I know that in some places parvo is bad, and more precautions should be taken...but if the puppy vaccinations are not given at the right time (intervals) or started at the right time, or the brand of vaccine is not effective....then you can give 10 sets of vaccines and they will not be covering parvo.
Have a titer done and then you will know. We've had members here that have had their pups get parvo at 6-7 months of age...after they have had all of the shots...it was because immunity had not happened.
If all of the puppies in the puppy class have had their sets of vaccines, and have proof...I really would not be too worried.
I would be more worried of owning an unsocialized Rottweiler.
Gina