Simple: he didn't find these names in *Ev because not even the brothers were named there.
It would be very strange that Canonical Luke was based on Matthew and opted for the deliberate omission of the names of the brothers of Jesus.
Note that Acts betrayes the need of having brothers of Jesus recognized fully in the Church, but the omission of their names continues and this is surprising on the traditional view (that Canonical Luke-Acts preceded Marcion).
Why Canonical Luke never says the names of the brother of Jesus
Re: Why Canonical Luke never says the names of the brother of Jesus
Here we see the greatness and decadence of Canonical Luke:
a gospel that is the more small-minded of all in his clumsy corruption of *Ev (he omitted the names because in *Ev the same brothers are absent),
..and yet the gospel without which we couldn't verify that *Ev preceded even Mark and Matthew (where the names are given to give ontological consistency to otherwise phantomatic brothers).
a gospel that is the more small-minded of all in his clumsy corruption of *Ev (he omitted the names because in *Ev the same brothers are absent),
..and yet the gospel without which we couldn't verify that *Ev preceded even Mark and Matthew (where the names are given to give ontological consistency to otherwise phantomatic brothers).
Re: Why Canonical Luke never says the names of the brother of Jesus
I suspect that the original Gospel (proto-Mark) also did not include the names of any family members. Because neither Luke 3-24, nor *Ev, nor the Gospel of John identify the names of the family members of Jesus. Only Matthew and Mark (and Luke 1-2) do.
I don't think that if proto-Mark had these names that they would have been dropped by everyone else.
So it make sense the names were really added much later, and were put into canonical Mark by the editor of the four Gospel collection when harmonizing Mark with Matthew.
So proto-Mark did not include the names. proto-Luke, *Ev, John, etc. all derive from proto-Mark, either directly or indirectly, which did not have the names.
I don't think that if proto-Mark had these names that they would have been dropped by everyone else.
So it make sense the names were really added much later, and were put into canonical Mark by the editor of the four Gospel collection when harmonizing Mark with Matthew.
So proto-Mark did not include the names. proto-Luke, *Ev, John, etc. all derive from proto-Mark, either directly or indirectly, which did not have the names.