ὡς ἕκαστα—this use of ὲκατερος and ἕκαστος with ὡς and without a verb, after appearing in Herod. and Thuc., first reappears in Aristotle.
ἐπὶ πολὺ—as often, this replaces an accus. of the object.
ὅπως ἂν ἀπολισθάνοι—ὅπως ἃν appears with opt. in final clauses in Homer, Herod., only here in Thuc., and four times in Xen, and in Aesch. Ag. 364.