Not safe at all! It would imply many risks, the worst of them would be the agressive Paramesotriton tearing up the poor H.orientalis.
You have to consider that Paramesotriton are territorial and agressive and MUCH bigger. They could coexist together for a length of time with no apparent problems, then one day there would only be a suspiciously guilty looking fat newt. In addition to that, there are other problems like exchange of patogens, competition for food, stress (this is a big ones too)...
That mix is definitely a tragedy waiting to happen. You can find a lot of info in the CC articles and around the forums about mixing.