Some projects have multiple versions undergoing translation at the same time. In such cases it could be useful to be able to copy modified (better) translations from one version to the other, even where the other version has an Approved translation. The copy could be an unconditional "overwrite", or for "merge" it could use the same rule as "zanata push mergeType=auto" (ie only replace the translation if the replacement does not appear in the TextFlowTarget history). Another option might be "latest" which would compare modification times.
Is modification of the clients in the scope of this bug?
If the client had a separate copytrans command (which it really should have), I would say yes, we should add the new options to it.
Reassigned to PM
Migrated; check JIRA for bug status: http://zanata.atlassian.net/browse/ZNTA-319