R_Combine vs. Combine on newborn twins

[Pavol Hnila]

Hello,

I am combining two C14 dates from two separate skeletons of newborn
babies (0-2 months according to anthropological evaluation), who were
buried in the same tomb (earth-grave, not a multigenerational tomb), and
who were twins with the same mother (according to DNA-analysis). I am
aware of the recommendations to use Combine function on dates from
different  samples and R_Combine on multiple dates from the same
sample/source. However, in this particular case I suppose that despite
these samples coming from two different individuals, their C14 reservoir
is very likely the same (same mother, same environment), so the
R_Combine function should be acceptable for combining them. Or is it
still risky and should the general Combine function be used instead?

Actually, with my particular dates I see no real difference in the range
of calibrated results - as if it had no effect whether the dates get
combined before or after the calibration. Yet  before I proceed with
examples and some related questions, I wanted to clear the principle
question about the adequacy of R_Combine.

Best wishes,
Pavol