If 2 .vstsound files have the exact same names (not similar, the same) then they are redundant & you only need one copy.
Also there is no need for any of the content if you don’t intend to use it. Cubase will function fine without it. So you could just trash stuff you don’t want if space is an issue.
You don’t need both. The HALion Sonic Selection is a small curated subset of content from the 30 GB HALion 7 library. If you have the full version of HALion, everything from Sonic Selection is alredy there.
Are you sure of that? A few weeks ago I setup my Media Bay results columns to show the Library Names. Since then I’ve noticed that some presets are from Sonic libraries and others from Halion 7 (and a whole bunch of other libraries), but the same preset isn’t listed in more than one library as far as I can see. This is just a passing observation and not something I’ve explored in any detail. My impression is that the various libraries don’t overlap. So every version gets the Sonic library and then as you move up to more powerful versions more libraries get included - but they add together without duplication.
It could be that what Sonic Selection content is is stuff from the HALion Sonic 3 library (which is a separate product with its own 29 GB library). But if you want further confusion on the matter, there’s also the HALion 7 Sonic Collection, which should in theory be the free version of HALion with the full content from HALion 7 but the library sizes don’t match (it has the same 29.95 GB size from HALion Sonic 3 instead of the 30.32 GB from the 7 content.)