How did the Erin Hunters come up with the naming system?

Like, I bet it took ages! And how many prefixes and suffixes are there? Probably over 100. Here’s some names: Spottedheart, Mistflower, Reedclaw, Waterwish, Oceanflight. Can you come up with more? Like I said, there are so many names! Questions is: “How did the Erin Hunters come up with the naming system?”