This helps us make an Orb every Melee kill, every second. Orbs give us health, grenade energy, super energy, and armor charge for Lord of Wolves ammo (Special Finisher) which will also activate Overflow on Mirror Imago.
The amount of grenade energy we can get has no cooldown. Whereas impact induction would have a cooldown.
Skullfort gives you back 100% Thunderclap energy every kill, so each kill makes Orb.
If you are having a hard time fitting 3 Heavy Handed in your armor, I would recommend using D2armorpicker.
When finishing selecting your exotic, stat distribution (as well as fragments).
Pay attention to the small icons of: Mobility, Strength, and Discipline. This means that you will be getting a "1" somewhere in your armor. 3 Heavy Handed = 9 slots, 9 + 1 = 10.
Then take that to DIM. Make sure everything of the build is there, as you might need to insert mods like Facet of Hope or even change your supers/abilities (you can put armor mods like Siphons and Reaper in game), then apply it to the game.
Again, you might be getting a "1" somewhere in your armor. Find it, then swap stat mods.
For example you might have a "4" Resilience on Arms, and "1" Mobility on Legs. Swap them so that "4" goes to Legs and "1" goes to Arms.