It's likely that your devices are on a variety of different BSP & LG versions if that is what you are seeing. A8 and A7 are the primary Android releases but there are sub versions of BSP and LifeGuard. Turn on the OEMVersion property in your inventory view to see the differences. This means that not only DataWedge, but many of the other core system applications are also on different versions until you clean that up and standardize. 

DataWedge is a system app that is part of the base OS provided by Zebra. Updating DataWedge therefore requires that you update the device OS version via Zebra's LifeGuard program. The devices do need to be covered by an active software support contract to be eligible but assuming they are you should be able to download the update .zip files directly from the Zebra support page for the individual device models. You can then upgrade the devices using SOTI by delivering the .ZIP files to the /sdcard/ on the devices and using the install_system_update SOTI script to execute them. Note that not every LG update includes updates to system apps like DataWedge, but many of them do. 

TC56 Support Page:

Full BSP & LG Update Zips:

Release Notes showing DataWedge version: