Avoid Dragon Ogors. GW can't balance them worth a darn, and they are constantly overpriced for what they do. Warherd is also a bit overpriced, but at least playable.
I think the truly strongest way to play them is with at least one big brick of Bestigors (if not 2), and I've seen a lot of good lists taking advantage of one full stack of Ungor Raiders jumping in from the side of the board with a support hero and just unloading a bunch of shots.
Beasts are cool in that there's a lot of different ways to play them, you just have to make sure you build around an idea instead of getting a scattered, unfocused list. Was there a Herd you were thinking of going for?
You want at least one Cauldron of Blood, I think. I haven't seen much DoK in the 2019/2020 meta, but I think the Cauldron is still an important piece. Otherwise yeah, brick of Witch Aelves, dropping in Heartrenders, Hag Queens (though most people run 2+) is really what you want from the ladies.