Explosive arrow - fuse stacking

Explosive Arrow has a mechanic of dealing increased damage if the target has more arrows stuck to them. At the Wiki it says that the base duration is 1 second and the maximum fuses stuck in an enemy are 20.

So to be able to reach the maximum fuses charges a player need to fire at least 20 arrows per second, is this right? Because it seem a quite unreachable value.

I'm using explosive arrow with ballista totem, even having multiple sources of fuses, it sounds quite hard to achieve maximum fuses.

Is this the way it is intended to work or I'm missing something?

Plenty of attack speed, have barrage support in ballistas to help with stacking them.
It can be done

You can also use Barrage Support as one of your main links for bossing, either manual gem swap or have a 2nd bow to use on weapon swap (or both on chest/bow) but the latter I find gimps builds.

You want to get as many sources as +arrows/projectiles as possible. Dying Sun flask gives +2, you can get +1 on a Shaper or Warlord quiver. All bows can roll +2 arrows as a suffix (these tend to be very expensive). Deadeye can get +2 arrows.

Barrage Support gives 3 extra arrows at a cost of doing less base dmg, but with enough sources of +arrows it's worth it.

I'm not sure if the totem EA fuses overwrite or just mix in with your own fuses but generally speaking the totem skills will be doing less than you (Ballista Support and/or Multi Totem Support have less dmg/atk speed).

Whatever you end up doing though just aim for +arrows everywhere, and atk speed of course.

EA scales well with gem levels as well but for the fuse concern you'll want additional arrows/atk speed.