Apparently Holy Shotgun is going to be big this season!
I haven’t played Crusader in a while and I think I never played Holyd Shotgun! 
At any rate I found this build guide
https://www.icy-veins.com/d3/crusader-aegis-of-valor-heavens-fury-build
They use a pig sticker.
Why do they do that? Isn’t there many other better weapon?!
If you read the guide you wouldn’t have to ask.
I followed all the seemingly relevant link. Did CTRL+F “pig sticker”.
It just say that it could be replaced with InGeom.
A bit light in term of explanations…
Sorry, I don’t have your amazing read between the line skills!
Care to share instead of gloating? 
From the guide:
Surprisingly or not, but in a build where fast application of steadily increasing damage is paramount, you will be hard-pressed to find a better weapon to wield than Pig Sticker Pig Sticker. While lacking any flashy bonuses, this noisy knife more than makes up for it. First, it has the superior attack speed of the dagger weapon class (1.5 base); second, it rolls up to five primary stats, meaning it can have Damage %, Area Damage, Cooldown Reduction and Increased Attack Speed, and have it be optimized with a Strength augmentation. And third, its unique bonuses vs. human and beast enemies are multiplicative in nature and can lead to massive damage spikes in certain rift compositions.
But there are other possibilities and set-ups that you can go for.
strange… when I first did CTRL_F “pig sticker” this didn’t come up… (but it does now)
I think the text seems dynamically loaded with Javascript and my internet is super slow right now… might be that… so confusing!
Today I have tried the sunkeeper. And I was dissapointed. AS is not enough even for receiving all of 20 stacks; in solo not enough life per hit and the most important thing that is your animation became so slowly, that you`re dying more often and skip a lot of “shots” of you shotgun.
True, the table of content in the guide didn’t show up at first so the explanation could seem to be missing.
There is also this thread with another build:
It is a shame that a Crusader running with a ‘tooth-picker’ weapon, not really aligning for Holy Avenger.
For me it is a big pull-back to use that build, but will try one-day regardless.
Would be nice from Blizz to bring a suitable weapon instead of it.
I actually really like that there is an “open” cube weapon slot with this build. It opens options for the player, and allows us more choice.
I checked out blessed shield, and TOTALLY wanted to include the echoing fury with that build, but could not, because it was locked in by 3 weapon powers with multipliers. You could say the same for channeled meteor shower on wizard.
Skycutter works pretty well, i got a primal one in the first days of the seasons, and no decent pig sticker yet.