Death’s gate has been shown to be faster/stronger “as usual” on regular pet builds over hybrid builds, it’s also why it got nerfed last, because it was just too strong for regular pet builds, and it’s been such a consensus by the pet testers that DK just wasn’t even close by comparison, this not based on paper math but them trying testing and posting Death Knights at the time.
Last round of feedback, in attempt to get it buffed, Zantai outright questioned what it needed buffs for when it was clearly so strong, until realizing “oh, you’re using it on a Death Knight - well yea that’s always going to be behind”(paraphrasing since i didn’t snap the direct quote)
So, why do you not notice that much of a difference, if it’s basically “settled” balancing that ritualist/cabalist would be stronger with it than death knight? - well it might come down to overall build and or playstyle
Since GS? was straight up responsible for the Death’s Gates nerf on necro side, maybe he can add more on the regular pet build v “hybrid” pet DK build performance/strenght on it
on topic, i kinda puzzled at the note withcing hour is underused, when it’s used in 2 very strong “recent” post builds 
[1.2.1.2] Witching Hour's undead army Cabalist! [1.1.9.7] The Pet Candulas, Corruptor of Souls Cabalists Crucible 4:20
rest of the items/notes seems relatively on point from my casual experience and browsing