Canon stores the digital "value" for White Balance in the Exif of the Raw data -- it is proprietary data, that is, it is not a "direct" value that other software can just read and apply. So, software like Lightroom reads digital data and gives a "best guess" which temp/hue will be set.
I don't know the "stuff" that goes into this but it is not surprise that different cameras would have some difference as to the digital values that are set. Fortunately, the three values you show are pretty close, but when shooting Raw it's good to be prepared to tweak the WB even if you are processing in DPP, which knows about the digital values.