In The Bronze Bow, why is Rosh angry that Samson left the cave without permission?

When Daniel returns to the cave after a prolonged absence, he notices that Samson is not present. Usually, the giant is the first to greet him, as Samson believes he owes his life to Daniel. Furthermore, Rosh had ordered everyone to lie low for a while while the public heat on their band died down; Samson has obviously violated this order.

"Where's Samson?" he inquired.

Joktan shrugged. "That's anybody's guess. Samson has his own rules."

"Rosh lets him?"

"Rosh l-leaves well enough alone. If you ask me, he's sorry he ever got the brute. But Samson earns his keep."
(Speare, The Bronze Bow, Google Books)

Samson returns with a stolen sheep, which is good news because the band is hungry. Although Rosh, like all the others, eats his fill, he is clearly angry with Samson for disobeying his orders. He is also unhappy because Samson is so obviously devoted to Daniel instead of to himself; Rosh wants to be in total control of the bandits. However, he does nothing to punish Samson for three reasons: first, Samson is very tall and strong, and could probably kill many men before being killed; secondly, although he disobeyed orders, he also fed the band in a time of need; thirdly, as they believe Samson to be of below-average intelligence, it is entirely possible that he did not understand the orders. As long as Samson remains useful, Rosh will accept a certain amount of disobedience, but as seen later with Daniel, there are limits to his patience.