Lewis's birth date is based on an estimate that he is the oldest living son at the time of the 1766-68 warrant and survey. He was born after the first Christian Heinrich and before the second.
Looking back into the previous generation AND into his personal interactions with others during his lifetime, one would be hard pressed to find that he was anyone but the son of Johann Franciscus Bibler.
He was old enough to buy land before 1769, but young enough to be a foot soldier on a mid 1770s muster roll, meaning he was born some time in the 1740s in Germany.
He is not known to have had any sons, certainly not one old enough to be his brother. He may have had children who died young, but if so, the information is lost, as he was a Baptist (no infant baptisms) and attened churches where no records exist.