As mentioned above Halion 5 has no real input directly in to it’s samplebank.That is a niggle indeed, and so you can’t f.e. route signals from cubase directly in to it. The comparison with Kontakt is correct in that sense. But for me kontakt is way less user friendly then Halion, but that is another discussion.
Except the input Halion is functionwise a complete sampler, and you load in (already recorded) samples from anywhere you want.
You can drag and drop them from browsers or from main workflow windows or the internal browser.
From there one you start working with the sample mapping, and then you connect it to the synth engine or even combine it with the other synth/drum engines that are delivered in Halion 5. The tree is key to working with Halion, and understanding it’s menu structure is vital. (as with any synth)
The problem with old scool sampling behaviour from the past that seems to have being dropped by many programmers is that you need the VST-framework te be configured so it is recognized as having INPUTS in to the VST. THe next step is to route the outputs of one or more channels (audio of instruments) to the inputs of the sampler. E.g. NI Reaktor is such a tool where you can have loads of old scool samplers integrated in to the package. I’ve never figured out why this type of functionality is not omni present anymore, but i guess the huge amount of available sample banks is one of the reasons that they have done it this way, and obviously the fact that cubase in itself has sample functionality integrated is another. (just press record on an audio track and you are in fact sampling in cubase. Next thing is if you want more functionality is to drag/drop it in to Halion)
good luck and have fun!