Diviner set didn’t get hit with nerfs that much. Set even got an extra -2RR (which might not seem like much, but remember that the 5 RR nerf from each mastery skill actually made a difference).
Build also only has 1 type of Pet: Reap Spirit, fully maxed. Rest are all Support skills.
And Reap Spirits are notorious for not dying due to their insane resistances (100 to everything) and even when they die, low CDR unlike “Primal Spirit too OP, can’t have 0 downtime”.
So you can go full on offensive without worrying about pet defense unlike in Briarthorn or Familiar builds.
Now, Pets got a bit of stats baked into them sure. But if you had used say 1 full set and 3 pieces of another set (or 2 full sets in case of my Will-O-Wisp), you got hit by 2x nerfs.
Like for eg: if 2 sets lost +200% dmg in total, but pets get +100% dmg each as compensation for the dmg lost from their individual sets (my own made up numbers for easy explanation), you are still down +100% dmg. Same for HP values.
Then there is the lost Crit damage, which is rather huge.
But this particular build doesn’t suffer from any of that. It still gets more than +1500% Pet dmg, has 170% Crit dmg etc…
Ofcourse, you can’t look at the stats in a vacuum, since compared to say, my Fluffy Squishy, whose stats are more or less permanently on (even if much lower), there are a lot of temporary procs here that push the numbers high.
There is also much more to manage compared to the laid back nature of my usual builds (imo).
But the results in the previous patches spoke for its power and based on it and the changes, said power while lower, shouldn’t have taken as much of a hit as say… a conjurer build.
So, the player side remains the same.
Pet side, only a small loss due to only having 1 pet and 1 set.
High dmg, Crit, invincible Pets.
I once said that this might be a contender to Fluffy Squishy. But then the RR nerf + vitality requiring every bit of RR it can afford, made me rethink that statement. But with the competition nerfed, I can safely say it once more.
But this is in regards to my builds and mine alone. And even then, it is all within the context of No Green MIs used. Also, my builds suck in Crucible 
Others might be able to come up with better solutions.
@Duskdeep86 even has his own version that he made much earlier (back when Diviner’s still had Aether conversion for pets, which made me not go for pure Reap spirit build): [1.1.5.2 - 1.1.6.2][Vid] Diviner Set | high Crit vitality Pet | Ritualist | SR 100
I don’t know if anything needs to be tweaked for that ^, but it was strong as hell back then and was the inspiration for mine.
If you want Crucible focused builds, @Crittrain can help you with that. His [1.1.9.0] KaosKats V2 Taking pets to the Darkside || 5.18 Cruci || remains strong even though no more SR 120 like shenanigans. Also is a Briarthorn Conjurer, so there is that.