I often do combinations of both, where eventually most events semi common will be under 1 event system.
Mainly because:
Even with a small multiplayer system, editing existing events, become tedious and bug prone due to 'forgotten' edits, or incorrect edits, because you you have to do a lot of things twice.
Having a singular system, with is host (or is not host), is, in my opinion, the slightly safer bet, because most events only occur once.
So for me is is more about the slew of aftermath work when tweaking existing mechanics.... I prefer to just edit once, vs, 'oh, forgot that, needs another edit' .... which lends itself for misleading the developer into tweaking other elements, because the first edit didn't pan out as expected. (Forgot something)
One tip, when combining events, make sure to update/add comments to indicate what the code does for who, but that goed for most of the events in any game really.