One physical idea sits under this whole family: pressing down hard. Press an enemy into submission and you have conquest; press vegetables under brine and you have pickling; press and roll the ground flat and you have a paved road; press your feelings down and you have suppression. The same three letters spelled with a final ש give you all of these. A second, older sibling root with a sin (שׂ) gives the sheep, the ram and the ewe, the animals you press wool from. Every word 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 verb pair is clean: pa'al לִכְבֹּשׁ is the active pressing-down (conquer, pickle, pave), and its nif'al partner לְהִכָּבֵשׁ is the passive (be conquered, be pickled). One verb root, many domains, all united by the gesture of pressing. The sheep words below belong to the homonymous sin-root and never take these verbs.
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.