It's been mentioned already but just thought I'd say I loved the Shapeshifting Hunter feat with a single level dip into Ranger when I was playing my dwarven druid. I coupled it with the world walker druid archetype to keep ranger's favoured terrains as well as favoured enemies. My guy was a middle grounder as you called it, but I found the favoured enemy bonuses really helped with the transition from caster to melee when they kicked in.
*Edit* Stats were, I think, 14 12 16 12 18 5, with dreams of eventual heavy armour.
I'm playing something similar right now, but I'm using the Goliath Druid archetype and mostly focusing on melee despite being a decent caster. It's a pretty potent combo... And just for fun I'm also using the magus variant multi-class for arcane pool fun and spellstrike. You lose a bunch of feats, but as long as you focus on shapeshifting hunter and power attack you'll do just fine. And I recommend heavy armor proficiency plus dragonscale plate.