Export xpub to sparrow. Use seed words to create full wallet in sparrow, compare addresses. Delete wallet and spin up a new seed on jade. Export xpub tosparrows, done. I'd also add pass phrases. And maybe bip 85 derivation (if jade supports it.).. If Jade supports XOR, you could create a wallet in sparrow, and xor it with wallet in jade.. That would he pretty damn solid. 

 Thanks for great pointers that will turn into a couple of constructive workdays right away! :-)