Most popular class/race combos

[DEFCON 1]

Seems legit, the Half-Orc Druid seems to be the oddity in that list, though why not?

True enough. We'd ordinarily go with the Half-Orc barbarian, but it turns out the Goliath barbarian just got higher votes than the half-orc and thus "claimed" the class. Which meant the half-orc just kept falling until it was either them or the aasimar for the druid, and the half-orc was just a bit higher.

 

[Yaarel]

Actually, the Awsimar do well as a Ranger.

 

[Yaarel]

These one-to-one correlations between class and heritage have limitations.

For example, I love the wizard archetype, and I like less the gnome archetype, and find the defacto flavoring of wizards as gnomes, a turn off.

Statistically, the wizard is more elf than any other heritage.

It helps to consider each heritage an assemblage of several prominent classes.

Again more granularity − especially to more clearly separate high elf from wood elf − helps alot.

 

[Yaarel]

Looking at the chart in the OP, convinces me stronger than ever.

The high elf and the wood elf need to be separate heritages.

D&D 4e, 13th Age, Forgotten Realms 3e, and others got it right. The concepts of high elf (aka sun elf, eladrin elf) and wood elf are too different from each other. They need separate stats and descriptions.

 

[Yaarel]

I am impressed how the defining majority of the druid class are (wood).