Unless I miss my guess, you are relying on some "traditions" as well: based on his tribe, we know when he served and when he was struck dumb and when John was conceived.
Do we not know that from a "tradition of men", i.e. which tribe was serving when the Temple was destroyed?
1 Chronicles 24:7-18
7 posted on 12/26/2007 12:51:15 PM PST by Uri’el-2012
(you shall know that I, YHvH, your Savior, and your Redeemer, am the Elohim of Ya'aqob. Isaiah 60:16)