Sorry I think I'm close to following you... In the other video the 'vendor' entry contained ['lodash', 'jquery'] and only those modules ended up in that common bundle. I follow that.
In this video are you saying you would you still have that same vendor entry? Because then I don't understand why the 'app' and 'animalFacts' chunks are being supplied to the vendor common plugin. I'd think without supplying any chunks (and only supplying the name) bundle.vendor.js would still only contain lodash and jquery, bundle.common.js would extract other modules common to the two apps, and the bundle.app.js and bundle.animalFacts each contain what is unique to them.
I think I'm missing something!