Sure, but I would say that Weim's have a very distinct look. Have you ever been to a dog show and seen what a truly well bred lab retriever looks like? They're miles from what most people that own a "lab" have in their back yard. I would just caution that with a dog coming from a rescue you never truly know what is mixed in with your "pure bred" whatever unless in the very rare case the dog has been given to rescue along with its paperwork. Please don't think I'm saying that the piece of paper is the end-all-be-all.
Off the top of my head I really can't think of one breed whose temperments can't be generalized or aren't predictable.
Agree, the look is so distinctive of some breeds that there’s no mistaking if they’re pure bred or not.
I had friends who had a lab, supposedly from a reputable breeder, and she was a lovely dog, but the dog always looked like she had some pit in her.