Yeah - that's a big "heck no" - Jewels are pretty similar to JDs, I wouldn't trust a JD with an Oscar that wasn't nearly large enough to gulp it down like a feeder.
JDs are known O-killers unless they're introduced to large tanks containing large Os and lots of cover, and the JD is just a pipsqueak when introduced. To me, it doesn't sound like you're likely to meet any of the above criteria, so save an O, leave it at the store.
IMHO: If your JD isn't shredding your Jewels, count yourself lucky (and don't push your luck by adding to the mix).