It is for backward compatibility. Back in the days, when Triebwerk etc. where still installed as self contained plug-ins, the installer was putting hundreds of single vstpreset files on your harddrive. When we discontinued those unfortunate plugins (in reality just a wrapped HALion Sonic SE, so just a waste of space and resources), we had to make sure those presets are on the system and started installing them via VSTSound file with HALion. It is only a few MB after all.
These days Triebwerk etc. come as VSTSound and run in HALion Sonic 7 or HALion 7, tidily managed by the Library Manager and searchable via media bay.
Quite a long story, but this is how it went down, if remember correctly
You won’t save much space and they will be installed again with the next update. So yes, but not recommended. Also in any case keep:
FCP_SMT_761_HALion_SP.vstsound
FCP_SMT_760_HALion_Common_SP.vstsound
Keep them! Some sounds will not be able to show a macro page. Also, you can use all those knobs etc. yourself in the macropage editor.
Yes, they are static and not movable. But again, they do not take much space, so should not be an issue on any productive system.