No - what for?
client-res.jar contains the res files for Ender client which is the base for Xcoms haven.rar which contains a haven.jar and a res folder - so you have haven-res.jar, Ender client-res.jar and Xcoms res folder for res files
you might exchange Enders haven-res.jar with mvguliks compilation haven-res.jar (to have all known res files and to avoid "resource can't be downloaded" errors)