King's Heart

Ezra 7:27
Praise be to the LORD, the God of our fathers, who has put it into the king's heart to bring honor to the house of the LORD in Jerusalem in this way.

I'm not sure what happened between Cyrus and Artaxerxes, his great-grandson, who is the king of the hour. King of kings, he called himself in the letter to Ezra, the teacher well-versed in the Law of Moses. I will research those chapters later.
The important thing here is that God put it into this king's inmost thoughts to honor the house of God. He offered Ezra everything and reminded him to buy animals for the sacrifice.
Maybe (without looking at the particular facts of the case) I need to be less worried about the moment. God has it in his hand. What about the generations who suffered in Europe till the time came to go to the new land? God works in the big picture. It's all present in one glance to him, and he touches up here and there. Speak to a king, then speak to his great-grandson. Nothing is lost. The train is right on time.