Comment # 3 on bug 1204956 from Benjamin Zeller

You can enable keep-packages per repo ( see zypper modifyrepo --keep-packages )
so that zypper does not delete rpms anymore after installing them. 

A possibility would be to use plain dir repos for all but one host, e.g. after
installing the packages on one host that has keep-packages enabled you copy
them to a shared directory that the others use as repository.