Can someone summarise the 'vibe' of the different Votann Detachments?

I'm coming back to the hobby (dragged, kicking and screaming obviously, by some new friends) after 15 or so years, and it's changed almost beyond recognition (not necessarily in a bad way!).

I've fallen in love a bit with Leagues of Votann, but I won't get to buy the codex until tomorrow. I've read through the core rules, but some of the terminology and the (necessarily) wordy descriptions of the detachment rules is hard to digest without some context from the codex I haven't got yet. So basically I'm wondering if someone would be kind enough to briefly summarise the detachments for me, in terms of a general vibe?

Some seem obvious: Brandfast is designed to be mechanised because units near vehicles get a bonus to shooting, whilst I guess Delve is close-combat oriented since you get Beserks as battlelines.

Needgaard seems like the "default" kill stuff option? Get YP for killing stuff, so be (even) more aggressive to get YP to spend on being better at killing more stuff.

I think I've worked out Hearthyfyre too: they're the 'heavy weapons dudes'. The elite options in the codex get better if you spend more YP on them, and you're incentivised to take more of them because they gain more YP for holding objectives with their elite leaders. That makes sense. Not my vibe, but I can see where it's going.

Persecution, Hearthband and Mercenary seem more complex though as I don't really understand what the rules they're changing 'do' in the first place.

Edit: Ok, Persecution seems to be about mobility and taking down big, tough things. Think I'm getting the hang of this already tbh!