So I could agree that the timing of the numbers being shown could be different. And if they were Smart, they set up an internal scripting language to show when the effect happens and did NOT tie it directly to when the server processes it. We do have a client/server relationship, so even if we got what we want here. You'd still see the HP bar the target move before the attack 'finishes' This is because they do not wish Animations to self nerf abilities.

As for multihit. The only effects we see do multiple numbers are those that apply their effect multiple times. Like a Barrage'd Straight Shot. For attacks that aren't doubled or tripled like that, they do their potency value in damage. To change it so other attacks that have multiple hits in the animation, they would have to divide the damage dealt (after potency and modifiers and such) by the number of hits. Again if they set up their internal scripting for this sort of thing properly, it shouldn't be that hard.

So this is heavily dependent on how they set up their effect stack script.