Even skimming through it discusses the coverage of wind and a not 50/50 system particularly to cover winter & night time. There is also discussion of a ~2% from "other" and how much storage capacity is required.
The article even goes into using wind & solar data for the simulation and reducing further the output to be conservative.
Additionally, mixing solar and wind is not as easy as it seems, because the two are correlated. If you have a major storm that makes wind energy impossible due to wind speeds above ~100km/h, you will also have clouds making solar energy unworkable. I'm not aware of any simulations modelling a 95+% solar/wind grid for storage needs, taking into account extreme weather patterns, grid topology, and equipment damage, but if you do then please link it.
I don't see any article linked in the comment I replied to. Perhaps you're mixing up two comment chains.
Assuming batteries are used for all storage use cases is one of the classic errors of energy system analysis.