Simple thought experiment to show how theft is a loosing game.
3 people are on one island and 3 on an identical twin island. On one island everyone is fishing. The fishers fish 4 hours a day and the rest of the day they read, write, build ships, cut trees and maintain their common house.
On the other island only two fish, read, write, bild ships and maintain the house. The third invests all his time in forging weapons and train to be the strongest. To sustain he forces the other two to gift him fish and a bed to sleep in the house.
Even in the case the other two do never revolt and accept all supression, their island lacks at least a third of productivity compared to the twinisland.
So whenever one of thos islands will be able to sail to the other island, it is very clear which island has the better odds to win this fight.