It depends, which model Orion are you talking about?
Also, radios don't always have all the options enabled. While an XTS3000 may be capable of P25, it doesn't mean that the radios flash code has the P25 enabled. It could be an analog only radio.
So, you would need to know the flash code for the XTS-3000, and be sure it operates on the same frequencies as the Orion.
For the orion, you'd need to know it worked on the same frequencies as the XTS, and if it had the P25 function enabled.
Crypto depends on the exact type used. You would also need to determine that from the XTS flashcode and whatever the Orion uses. If they both do AES, then they should be good to go.
There are a lot of little details in between that needs to be addressed, it isn't necessarily a slam-dunk.