If I was to look at designing a Druid these days I would look at making a Shape changing focused 1/2 caster with some beast summoning or controlling ability. This allows for both balance and flavour.
I kinda have something like that in my homebrew system, too. One of the defining traits about my "Priest" classes is that it is defined by its Channeling ability, rather than just a different kind of magic. So, cleric's channel divine (as we all know) and druid's channel "nature." That is, the natural primordial energies of the physical world -flora, fauna, elements, weather-related stuff, etc... Distinct from the "divine" energies which are directly siphoned off of deities/divine beings.
Their initial channeling effects are befriending animals, sensing "imbalance" (disturbances in the "Natural" Force, like undead, extraplanar energies, and power extreme [non-neutral] alignments), and countering "Nature's Charms" (faye, sylvan and elemental based charms & illusions, enchantments cast by other druids, etc...). Shapeshifting comes -as another channeling effect to choose from- a few levels later...in homage to my 1e/OSR sensibilities, I think it's 6th level.
All of this is a long-winded way of saying they don't get spellcasting until 3rd level and the spell progression trails those of the "Wizard" classes group by a couple of levels...so, not really a "half caster" in the 5e sense. But similar.
So, yeah. Given the options of 1 to choose from, the druid is a magic worker, i.e. spell caster or in the case of my homebrew "channeling" first, then spell casting), before and primary to "shapeshifting."