Experiment: how would you transliterate the following glyphs?

[nablator]

If you intend on writing an 8-shape, wouldn't you start going clockwise in the top loop instead of drawing a "c" first and then lifting the pen? (I still know very little about this). If you are right that they generally drew the c-shape first, this would be interesting, because like you say several glyphs would be natural "stops" along the same trajectory. And even though they could probably have formed the "8" in a different way, they still followed this trajectory to write it.

When I write an "8" I start anti-clockwise on top like a "c" but that's just me. I don't lift the pen until the end.

Writing two strokes instead of one, with the "c" shape first must have felt more natural to them than us, because they used to write cursiva and its Latin abbreviations -ris, -cis that are so similar to m, g. Also, they did not intend to write an 8.