Yes, on can use basically any MaintenanceScript and specify the targeted wiki instance by the --sfr option. It must be provided with a valid (registered) "group id" or "project name". The config-dispatcher in extensions/TuleapWikiFarm will then load the proper wiki instance and have the MaintenanceScript operate on it.

Regarding the concrete two scripts: Please run importImages.php before importDump.php. Nothing really breaks if you don't do it, but you may end up with wikipages that show "red links" instead of images, until one manually clears the parser cache (?action=purge). This can easily be avoided by first importing the files/images and then the pages that use them.

Here is an example of how those scripts could be called, given the Project is called testabc and has the ID 103:

php maintenance/importImages.php --sfr=testabc /path/to/data/images/
php maintenance/importDump.php --sfr=103 /path/to/data/output.xml

@rvogel @dsavuljesku any insights on that ?