נ־ה־ג carries one rich idea: to guide a course. The very same pa'al verb (לִנְהֹג) means both to drive a vehicle and to be in the habit of doing something, because both are about the way you steer, whether a car or your own conduct. Push the root into the causative hif'il and you get to lead, to rule. From there it radiates: the driver, the leader, the act of driving, the custom a community follows, and one's overall behaviour. One root quietly governs the road, the nation, and personal habit. Every word here is verified against pealim, niqqud included.
The same root runs through the verb system. Each binyan is a voice: it bends the one idea into active, passive, causative or reciprocal. Tap to hear.
The pa'al לִנְהֹג already holds both halves of the root: the literal (to drive) and the figurative (to have a habit / customary way). The hif'il לְהַנְהִיג is causative: to make a course be followed, hence to lead, rule, or institute a practice. The reflexive sense (how one conducts oneself) is carried by the hitpa'el noun הִתְנַהֲגוּת below. No nif'al, pi'el, pu'al or huf'al are lexicalized for this root.
Same root letters, different noun moulds (mishkalim). The mould tells you the function: who does it, the act of doing it, or the thing produced.
Strip the prefixes, suffixes and vowels. Three consonants remain, and the meaning lives there.