I mean, you certainly could go 6dh/14 druid, if that's your thing. Just know, druids in animal form do not benefit from the weapon combat style feats when it comes to attacking (So your free twf won't do anything while in wolf form). Shields still provide their AC bonus, but do not provide doublestrike% or PRR from the Shield Mastery feats either. Instead, druids who rely on animal forms for melee damage will want to take Natural Fighting (You take the same feat 3 times, instead of having three different feats).
While you might not see the greatsword (or other weapon, for that matter), you still get the basic bonus damage for wielding a two-handed weapon while in animal forms (That is, you get 1.5x your ability mod for damage, instead of the base 1x). So there's still a benefit to using your greatsword, even if you can't see the weapon.
Depending on what tree you're using, shield+weapon works well. For a dh/druid split, your best bet is probably still thf in wolf form, so you can take advantage of your sneak attack and the boosts in the Nature's Warrior tree.
Bear forms work better with Nature's Protector, which also has some support for barbarian/druid hybrids, and works equally well with shield+weapon and thf.