Yes, you can switch the same card from partner to partner. However ...

A minimum of one card must be linked to each partner account. The system will not allow de-linking a "solo" card by members; zero cards linked closes the account, and can only be done by RN staff. In other words, to transfer a solo card to another partner account, you need to add a "place-holder" one first to free the desired card for removal.

A reminder while I'm at it. If you run across a one-visit-per-month joint it means once per partner per month. In other words, an AA-linked charge closes out AA for that month, but all other partners are still okay; works fine to split the same visit between airlines at those joints as well.