Durable Model with Package name change

[Cognos91]

We have a durable model, with en-zw as the design language, and English, French, German as additional language. English is the active language.
We are trying to deprecate the existing package (for namesake, "Package 1") and rename it as "Package 1 Legacy" (legacy is added as a suffix).

In FM, when we change the English name to add Legacy, and publish the package, Package 1 gets overwritten - Package 1 is now seen as Package 1 Legacy. All reports/ and dashboards pointing to "Package 1" now point to "Package 1 Legacy" automatically. This is in the local development environment.
However, when I create an export and import this zip file (with the new package name legacy) to another environment, Cognos throws this error -
CM-REQ-4111 Object "/Team Content/Package 1" (of class "package") was not imported. CM-REQ-4337 The package 'Package 1 Legacy' from the archive and the package 'Package 1 ' in the content store are considered the same because their names match in one or more locales. However, Content Manager cannot merge these two packages because at least one locale does not match. If you want to merge these two packages, please make sure their names match in all locales. Otherwise, if you want to import this package as a different package, please make sure the target names are unique in all locales.

Is there anything that I am missing? This is a durable model. English name (active language) was changed to Package 1 Legacy.
Just to add - English and English-zw names were both changed to "Package 1 Legacy" where as French and German names remain the same as they were in the old package names.