I don't know why they seem to do that, but there are patterns and there are numbers that tend to have significant purpose in the Scriptures as in being symbolic of the purpose for when they are used. But other than that I don't tie it to the numerology as is so easy to do, and I don't tie it to anything else other than what it actually stands for. My hunch is this, that the numbers are repeated so the ones who were involved at that time would be able to remember what happened when, and to tie it to the event itself and why it was to happen, is because God wanted it to happen that way and not for any other reason.
Because they're really vague and the human mind, even subconsciously is selective in its acceptance and application of knowledge. That's how they get away with it.
People love to focus on what hits, and don't bother seeing what misses. This is why lotteries are so successful. Everyone sees a winner receiving millions of dollars and they run out to buy tickets thinking they might be similarly rewarded. They fail to see the millions upon millions of losing tickets.
It seems that people often seek to believe in something. In the case of numerology and what not, the interpretation is vague and as a result so wide, that it can be made to look accurate for any specific person's experiences.