You have to use the Ag Products - Same company, different Divisions and Completely different Target Markets - not many people do Crop Spraying or Harvesting Results in the Construction World!
So while One Trimble, it is not expected that these tools would typically show up in the same place and if they do we would expect the Ag user to have the Ag tools and the construction survey user to have the survey tools so that they can create and manage the data for the separate systems - the systems are typically provided with the tools required to manage the data to and from the system. The Ag tools do support some common formats - they are more GIS based so I would start with ESRI SHP/SHX files or standard DWG/DXF files. I don't believe that LandXML is used at all in the Ag space.
You have a pretty extreme corner case right here
Alan