Ben knew they would be crashing?
This is not ground breaking stuff, however, it’s worth mentioning. Since we know that Saywer, Jack, Hurley, Kate, etc. are stuck in Dharma time, perhaps young Ben has seen them in the past (over the next few episodes) and knows that they crashed on the Island in the future. He either possibly hears this, or assumes this to be the case. This could be the reason he has a list of names (may not be complete because it doesn’t include Jin, etc.) that match the losties that end up in the past during Dharma time.