Great insights, all.
In summation to this point we all agree the early acquisitions (Dynamix, Coktel, Impressions) “became” Sierra. Collector’s point about the sharing of code was an excellent point. Rudy brought up a pretty interesting question (and one I struggled with as webmaster of SierraVault): What do you do with games the companies put out before the mergers? What about when Sierra re-released them? Impressions had a lot of games on the market before Sierra and Sierra heavily pulled from that catalog in their Sierra Classics releases.
The digital archiving point made by Laine is excellent as well. While Ken and Roberta were out of Sierra in the late 90s and most of the early developers and game series we view as “core” Sierra were put out to pasture by the early 2000s there were still a lot of people getting up every day and going to work at Sierra. Were their efforts any less? Shouldn’t their games deserve some credit? A few years back I read a comment on a blog news post about the Sierra legacy from one of those employees and he made an impassioned argument that the “not Sierra” label was unfair. The VU to CUC to Activision hot potato handoff sucked but the Sierra name took a lot of years of mismanagement before it could finally be killed.