Okay, if the fact that the term “spell slot” is used makes the Ranger too magical, regardless of how supernatural or mundane the abilities fueled by them are, how about;
Survival Points. You get around 1/level, like Ki on Monks, and you can use them to fuel special abilities. You get some automatically, and some come from Favored Terrain/Enemy and other class choices. Let’s call them Wilderness Knacks.
For those of us who see the Ranger’s basic identity as fundamentally magical, some Wilderness Knacks are supernatural, and some straight up give you spells you can cast by spending 1/Survival point per spell level.
This would create a very unique class, that accommodates all three preferences.
@Charlaquin @Greg K what you think? All currently magical class features would be a decision point, possibly on a warlock style chassis where Knacks are chosen like Invocations. Seem fair?