Daniel 1: a colision of two cultures

Daniel and his friends were taken to the exile in Babylon in the the third year of King Jehoiakim’s reign, thus, they must have been one of the first exiles. They were from an upper class, intelligent and candidates to a leadership position, but first, they had to learn the Babylonian culture that dominated the world, specially Jerusalem.
They were to be treated as kings, so they were given the king food and wine. At first, it seemed a great privilege, but they refused because they did n´t want to be contaminated. They wanted to follow a kosher diet (for instance: don't eat pork). However, they were not as guests of the king, they were there as prisoners. They should obey the rules of Babylon. Would they obey and disrespect the kosher diet?
We read:

8-10 But Daniel determined that he would not defile himself by eating the king’s food or drinking his wine, so he asked the head of the palace staff to exempt him from the royal diet. The head of the palace staff, by God’s grace, liked Daniel, but he warned him, “I’m afraid of what my master the king will do. He is the one who assigned this diet and if he sees that you are not as healthy as the rest, he’ll have my head!”

11-13 But Daniel appealed to a steward who had been assigned by the head of the palace staff to be in charge of Daniel, Hananiah, Mishael, and Azariah: “Try us out for ten days on a simple diet of vegetables and water. Then compare us with the young men who eat from the royal menu. Make your decision on the basis of what you see.”

Instead of directly confronting Babylon, Daniel was clever to propose a test. What was the objective of the royal food? To make them better? So, why not try another diet that may be even better?
In fact, they were given permission for this diet after the ten days test. Not only that, but they were very succeeded after their three year training getting the highest scores.
We read:

19-20 And so they took their place in the king’s service. Whenever the king consulted them on anything, on books or on life, he found them ten times better than all the magicians and enchanters in his kingdom put together.