The tribes of Reuben and Gad want to settle the good grazing lands east of the Jordan

Numbers 32:1-19
The Reubenites and Gadites they came to Moses and Eleazar the priest and to the leaders of the community, and said, the land the Lord subdued before the people of Israel—are suitable for livestock, and your servants have livestock. If we have found favor in your eyes,” they said, “let this land be given to your servants as our possession. Do not make us cross the Jordan.
And here you are, a brood(窩) of sinners, standing in the place of your fathers and making the Lord even more angry with Israel.  If you turn away from following him, he will again leave all this people in the wilderness, and you will be the cause of their destruction.
We will not return to our homes until each of the Israelites has received their inheritance. We will not receive any inheritance with them on the other side of the Jordan, because our inheritance has come to us on the east side of the Jordan.
The tribes of Reuben and Gad want to settle the good grazing lands east of the Jordan. Their request is allowed, but only on condition that they help in the conquest of Canaan first.
Why?
The tribes and Gad saw the land of Moan was good for living, so they wanted to stay their as their inheritance, but when they mentioned to Moses and leader of Israel, they were angry with their idea. It is against the way of the Lord, it will cause them destruction. So Moses and leaders refused them.
But they took care their wife, children and herbs, and they will go with Israelite and across Jordan to fight with their brothers.
God's promised land is the best one, but they chose the land here, It looks good either, but away from his brothers, it makes them ruined before their brothers a few generation later.
How?
Peopel sometimes look the beauty of what we saw, but havn't confident to the Lord that the promised land is the best one, We chose the second one instead of the best one.