You don't need to protect from everything. Several of these issues are so rare that you're better off treating them than preventing them and your dog suffering side effects.
You should really just talk to your vet. There's way more to it than a simple chart. They know the pharmacology, effectiveness, and necessity of all these drugs.
My girlfriend is a vet, and our dogs only take Trifexis. It works for our animals, their lifestyles, and our part of the country. Her prescription might change for an animal with short fur that goes hunting a lot. It all just depends.
In addition to not needing coverage for everything, some of the treatments require prescriptions because they can be dangerous to the pup. An example is preventative heartworm medication can be devastating to a dog with heartworms. A blood test is done to make sure a dog is heartworm negative.
You should really just talk to your vet. There's way more to it than a simple chart. They know the pharmacology, effectiveness, and necessity of all these drugs.
My girlfriend is a vet, and our dogs only take Trifexis. It works for our animals, their lifestyles, and our part of the country. Her prescription might change for an animal with short fur that goes hunting a lot. It all just depends.