ἀρχὴ δέ, ἐξ ἧς καὶ ἃ νυνδὴ ἐλέγομεν πάντα ἤρτηται, ἥδε αὐτῶν, ὡς τὸ πᾶν κίνησις ἦν καὶ ἄλλο παρὰ τοῦτο οὐδέν
is this ὡς like ὅτι? then it depends upon an implied verb of speaking.
I think it means “as”, explaining what ἀρχὴ means.
you may be right, so it is like ‘like’
still i think it belongs to Smyth 3001ως with verb implied