As others have already stated. You do not want to add the AvH weapons pak to the eto. The latest release of the AvH weapons pak was used as the base for the pylons, weapons, guns, effects for the CFS3 ETO Expansion. From that point on as the eto was developed all of the above was improved and added to the point where we now have about one years worth of adjustments and improvements. To wholesale overwright the existing eto effects, weapons, guns, pylons at this stage would ruin the latest developments.
If you add an addon on aircraft which comes with extra pylons, guns, or weapons as part of the package,don't blindly overwrite any existing file within the eto. Only add the extra files if none exist in your eto install or the readme instructions state that the extra files supercede existing eto files.