νῦν δ᾽ ἐπειδὴ καὶ ὁ φιλοπονώτατος πόλεμος ἀναπέπαυται, δοκεῖ μοι καὶ ἡ ἐμὴ ψυχὴ ἀναπαύσεώς τινος ἀξιοῦν τυγχάνειν.
Is this καί of balanced contrast?
Yes, clearly, at least that’s what Smyth would call it. It’s an interesting twinned use, spotlighting the αναπαυ- doubling: the φιλοπονώτατος war in the lead-in, then his own overworked soul in the main clause. Very nice.
Yes, it’s nice the more so that I can feel it firsthand reproducing the same structure in Russian.