I would say that's as least worst as it gets if you are determined to keep as close to the regular Favoured Enemy/Natural Explorer frameworks as you can. Obviously for me personally, I'd rather just scrap both altogether, but I do get why that'd be unpalatable for some.
Well both were written poorly and with the wrong mechanics. How Id s do it:
Favored Enemy
you have significant experience studying, tracking, hunting, and even talking to a certain type of enemy.
Choose a type of favored enemy: aberrations, beasts, celestials, constructs, dragons, elementals, fey, fiends, giants, monstrosities, oozes, plants, or undead. Alternatively, you can select two races of humanoid (such as gnolls and orcs) as favored enemies.
Whenever you roll a Wisdom (Survival) check to track your favored enemies, Charisma (Intimidation) check to scare your favored enemies, or Intelligence check to recall information about them, you treat a roll of 9 or lower as a 10.
When you gain this feature, you also learn one language of your choice that is spoken by your favored enemies, if they speak one at all.
You choose one additional favored enemy, as well as an associated language, at 6th and 14th level. As you gain levels, your choices should reflect the types of monsters you have encountered on your adventures.
You can also gain one additional favored enemy by studying them for at least 7 days straight. This can be by observing them unaware of your studies or reading a manual about the nature of culture of the favored enemy costing 100gp per favored enemy you currently know.
I disagree with this. I think spells are a core part of the Ranger design concept and not a result of the features they are trying to implement. I think spells on their own are at least as necessary to the class identity as some of the things you mention.
It became core.
But it original was because the only subsystems for ranger stuff besides lower level tracking and surprise were spells.
IMHO, they should be infusions.
I ranger should be shooting a special arrow they crafted, warding camp with specially treated string, talking to other rangers with crystal balls and walkie talkies, and equaling their animal friend with a charm they learned that lets them communicate.
I just got the image of a high level ranger lord calling in air strike to a giant eagle with 2 very angry dwarves in their talons.