Ok I think I'm starting to see the flexibility of this method. I had a situation where I guessed the wrong DR position and still got a fix. Here's the map work below. I showed the island I found for proof
My navigator gave me a position almost 50 km away (the random mark to the north) but I know this couldn't have been correct, otherwise I wouldn't have run into the island.
https://imgur.com/a/q8AYP7D
https://imgur.com/a/xCvSuKu