Dear User,
That was exactly my answer, this behavior is controlled by the NATIVE_OVERWRITE_OLDER pre-variable and not by the NATIVE_OVERWRITE;
Initially FALSE. Determines whether the native setup engine is allowed to replace files that have been determined to be newer with older files that are included in the installation. Set to TRUE to permit the native setup engine to replace files that are newer with older copies (this is not recommended). This variable overrides the value of the NATIVE_OVERWRITE variable when FALSE, and the file being installed by setup is determined to be older than the file already present on the target system. The native engine compares files as follows: If both files are versioned, the decision is based on the comparison of the file versions (the installed file has to be a newer version than the present file). If none of the files are versioned, the decision is based on the comparison of file dates (the installed file has to be modified more recently than the present file). If the file being installed lacks version information but the present file contains version information, the file being installed is assumed to be older. If the file being installed contains version information but the present file lacks version information, file dates are compared.
... and in your case Both files share the same version, so it is not replaced.
Regards