Thank you so much, Jorg! While the API approach seems to be the best possible one, in our situation this might be a temporary solution since Site B would eventually move into the AEM Cloud. But I'll surely keep this option as a potential solution for any similar problem. 

We are migrating Site A to AEM as Cloud Service and have Site B which references articles from Site A via a component that points to the article directory of Site A.Since Site B would remain in the AMS setup while Site A migrates to AEMaaCS, we are anticipating there could be a content mismatch for ...