it all depends on what complexity you want …
the thing Ive found is, with the power the Hapax has, often I dont need the extra complexity of (e.g) my Octatrack - if anything, having an additional sequencer adds (unwanted) extra cognitive load…
figuring out how I integrate the two sequencers? (*)
so I enjoy my Octatack, but when using the Hapax, it often gets used pretty simplistically.
and frankly, I tend to use it much more for its fun ‘mangling audio side’… than sample playback.
for simple sample playback (OP doesn’t mention how much live sampling is required here?!),
I often resort to the Rample… though 4 tracks is the main limitation (Ive considered adding another one!)
currently, Im thinking, Id like to add a more complex multi-layer sampler … e.g. with sample per velocity/note.
for that, I think Im going to use my Raspberry PI + PiSound… pretty simple to setup, and alot cheaper than suggestion made here…
sure, doesn’t have the hands on nature (***) , but most of the control is going to from the Hapax anyway (via midi), so I kind of like the idea of a black box (well grey) that just does the job 
also has the huge benefit, I don’t need to buy yet more gear (as I already have the rPI+PiSound!), and frankly, Im getting tired of this constant… I just need X 
(*) yes, it also gives extra flexibility, which is nice sometimes… but often too much choice can be a disadvantage when making music.
(**) obviously a rPI can pretty much do anything, from sample playback, recording, and anything else you need.
(***) actually, I can control via a web-browser over wifi,
also I have an electra one, so that could add a huge amount of hands-on capabilities.
with added benefit it’ll use same midi, as I can use for automation from hapax