Hello mumlif, welcome to the forums!
I'll first start off by saying there is no way for a moderator to know where every player is located. We also did not design the neighborhood merge system, and I also believe this needs to be improved.
That being said, if that player is a lot of eras ahead of you, either he or you may get merged out (mattering on the rest of the hood). If you want peace, try befriending that neighbor or asking if there's anyway to prevent him from plundering you. If you want revenge, try to see if another player in your neighborhood is able to attack/plunder that neighbor. As Estipar stated, if you're collecting your productions on time, there will be nothing for the attacker to plunder.
This being Korch though: everyone did start the game quite recently, so shouldn't the player who is progressing faster gain some sort of advantage over their neighbors?