Yes & No...........
If you find a good Breeder then stick with them - not all folks produce healthy high quality animals.
Also, buying from a different person does not, necessarily, indicate that the stock is unrelated. They too may have purchased animals from the same person as yourself.
Again refer to a good Breeder who can inform you of their stock's lineage as most will source animals from reliable friends or people with whom they have an excellent relationship & can verify their history.
In a 'nutshell' ask questions - if the seller is unable/unwilling to respond then move on to another person who is more knowledgeable.
Lex