While not quite as at odds with each other as the component classes of the artificer/druid pairing, the druid and herald classes definitely are a study in contrasts. Druids run on a devotion to nature and learn heavily on spellcasting and their supernatural Wild Shape feature with Wisdom and their primary ability score, whereas heralds are a Strength/Charisma class focused around ideological fervor and force of arms. Mechanically, there’s some substantial friction, lessened somewhat by the herald’s secondary spellcasting (which reduces the loss of spell slots over a non-casting class like adept or ranger) and the fact that both classes have access to their entire spell list and prepare, allowing a player to work around a middling casting ability in one or both classes by picking spells that rely on it less. Flavor-wise, there is more synergy than one might expect, if for no other reason than a strong devotion to the preservation of nature or something adjacent to it is perfectly valid as a herald’s defining ideological priority. A stronger focus on druid will give you a zealous champion of nature that relies mostly on their spells but who can pull out a sword when things get up close and personal while a focus on herald levels will give you an ideological champion with a bit of shapeshifting and some extra magic to call upon. An even mix, while perhaps not the most optimal choice looks like it’d be a lot of fun in this case, with a good balance of martial, shape-shifting, and spellcasting abilities available, allowing the character a high degree of versatility [[Synergy Feats for Multiclassers#Druid w/ Herald|Druid-Herald chains and ideas]]