Druid3 is for the huge stat boosts via hengestone. Sterea trofh’s 15s invuln with a 30s cd is quite nice as well.
And druid3 has a lot more dmg due to lycanthropy to boot.
Druid2 is not remotely as good, but still gets sterea trofh and transform + regular value stat attributes.
That being said, diev does not need druid. It’s just a solid option. And druid currently does not work well with Miko.
Diev3/Miko/PD2 like @s1lv3rw0lf said is a very nice all round build though.
And keep in mind Clap is likely subject to change, It’s intended to work on select objects & circles but atm only works on diev statues. Not sure how it will change though.
In theory clap + sterea trofh and/or clap + stonehenge would be very good but neither work atm and are not guaranteed to work either.