I work on a 0nuBB search doing detector R&D, this is spot on, but has 2 extra components. The three elements needed for explaining the asymmetry are:

1. CP Violation
2. Lepton or Baryon Number violation
3. Interactions out of thermal equilibrium

These are the Sakharov conditions for Baryogenesis/Leptogenesis. #1 has been observed via the weak interaction but not in large enough quantities and is not observed via strong interactions, #2 is what proton decay and 0nuBB searches look for, and #3 can be, at least partially, explained by the expansion of the universe as a non-equilibrium interaction.

To get from leptogenesis to baryogenesis requires theretical physics I only barely understand using particles call sphaelerons that convert leptons to baryons.