What's your question? Ask

I would have grown, just, one tree by itself in container. This is, purely, ornamental (some places group trees together in container to make it appear more full) and not meant to live for very long.

In order for the trees to perform at their best, they will need to be separated and placed into separate containers until they are ready to be planted in ground.

In can be very difficult to keep such a massive and needy tree in container. I would recommend planting in ground once established.

Here are some articles that will help:

https://www.gardeningknowhow.com/ornamental/trees/willow/grow-a-willow-tree.htm

https://www.gardeningknowhow.com/ornamental/trees/tgen/growing-trees-in-containers.htm

This is unfortunate, but sometimes transplant shock is hard to avoid.It looks like one may be a little more hardy than the other, as this one looks to have succumb to overwatering. This tree needs moist, well draining soil. But it should never remain saturated for long periods.

This can be a sign of overfertilization, as well, but it would have to be in compost, without cutting the compost with soil, or it had to have been fed way too much for this to be the case.

Sometimes, it can recover, once the environment is more favorable for the tree. This article will help you to give this tree proper care:

https://www.gardeningknowhow.com/ornamental/trees/willow/dappled-japanese-willow.htm

This article will help you with common problems as they arise:

https://www.gardeningknowhow.com/ornamental/trees/willow/dappled-willow-problems.htm

This could be a Bay Willow. You can take samples to your local extension service, where they can smell and inspect the plant, further. This link will help you to find the closest to you:

https://www.gardeningknowhow.com/extension-search

You would need to ask the vendor where you got the tree to know, for sure. If you do not know the origin of the tree, then it would be hard to say. You could have an arborist come out, or your local extension service.

This link will help you to find the closest local extension service to you:

https://www.gardeningknowhow.com/extension-search

From everything I've read, they should not be planted in a residential yard. The roots will not only affect the foundation, but any underground pipes or other structures on your property. I would advise removing it and replacing it with a tree suitable for residential landscapes.

Most likely the owner is pruning them to keep them off the ground, which can be hazardous to walk under or see around while driving. If not pruned, they would continue growing to the ground.

https://www.gardeningknowhow.com/ornamental/trees/willow/weeping-willow-pruning.htm