1. Not the same. You cannot make anywhere near the same progress by testing than having the engine in service.
2. Why do you think that Russians airlines flopped? Hint the engines were nowhere near as good as western ones.
OK, you are entitled to your view but logically I do not see the sense in it.
Russian commercial industries flopped,due to lot of factors. Despite having a very successful military sector. I will say they are currently even behind China in commercial section. They do have a lot of commercial planes but none meet FAA or non competitive in commercial market. Its not easy to design FAA standard commercial plane while being competitive at the same time. We do have a huge aviation market with many state owned airline to make any product a success if we want to. This is the luxury Russian do not have
This is a very good video explained C919, unfortunately, it is in Chinese only. But its very good info for those who understand Chinese.