All of them have quite different structures, and the reasons for choosing those structures have been clearly explained in published research papers.

The structures of the US "SOTA" models are unknown and nothing useful has been published about them, so they certainly were not a source of inspiration for China.

Big LLMs like those published by the Chinese companies must have been trained on a huge amount of text, images etc. and the training sets cannot have anything to do with the data hoarded by OpenAI and Anthropic, though they must have been gathered by the same methods, e.g. scanning the Internet and paying "pirates".

The only thing that could have been done by the Chinese companies, though for now there exists no evidence, only allegations, is that they could have used for post-training their models results of queries to US models, made by accounts which have breached the ToS, which forbid the use of the AI services by competitors.

If this really happened, this is a breach of contract, but there is no way in which one may say that the Chinese have copied anything or stolen any kind of IP and the effects of such a post-training can provide only an extremely small fraction of the information embedded in the weights of a model.