τούς δ’ ἵππους ό ἄγγελος άγει έκ τού Ήλλεσπόντου.
Just a small correction. The Hellespont is not ὁ Ἡλλεσποντος but ὁ Ἑλλησποντος, the sea (ὁ ποντος) of Ἑλλη (Helle), who fell off a flying golden ram sent to rescue her and her brother from their wicked stepmother, and the sea she fell into was named after her. Aren’t Greek myths fun?
According to F. W. Danker’s third edition; In narrative δὲ often does nothing more than connect the next event in the story line. In combination with other temporal markers δὲ is sometimes left untranslated.
Matt. 25:19 μετὰ δὲ πολὺν χρόνον ἔρχεται ὁ κύριος τῶν δούλων ἐκείνων καὶ συναίρει λόγον μετ᾿ αὐτῶν.
Matt. 25:19 (NRSV) After a long time the master of those slaves came and settled accounts with them.
Louwv & Nida 1990.
89.87 καί; δέ: markers of a sequence of closely related events — ‘and, and then.’
καί: εἰσῆλθον ὑπὸ τὸν ὄρθρον εἰς τὸ ἱερὸν καὶ ἐδίδασκον ‘at dawn they entered the Temple and taught’ Ac 5:21.
δέ: Ἀβραὰμ ἐγέννησεν τὸν Ἰσαάκ, Ἰσαὰκ δὲ ἐγέννησεν τὸν Ἰακώβ ‘Abraham was the father of Isaac and Isaac was the father of Jacob’ Mt 1:2.
89.94 δέ: a marker of an additive relation, but with the possible implication of some contrast — ‘and.’ Παῦλος δοῦλος θεοῦ, ἀπόστολος δὲ Ἰησοῦ Χριστοῦ ‘Paul, a servant of God and an apostle of Jesus Christ’ Tt 1:1.
89.124 δέ: a marker of contrast — ‘but, on the other hand.’ πολλοὶ γάρ εἰσιν κλητοὶ ὀλίγοι δὲ ἐκλεκτοί ‘many are invited, but few are chosen’ Mt 22:14; ὡς δὲ ἀνέβησαν οἱ ἀδελφοὶ αὐτοῦ εἰς τὴν ἑορτήν, τότε καὶ αὐτὸς ἀνέβη ‘but after his brothers went to the feast, he also went’ Jn 7:10.
89.136 μέν … δέ; μέντοι … δέ; μέν … ἀλλά; μέν … πλήν: markers of sets of items in contrast with one another — ‘on the one hand … but on the other hand.’
91.4 νυνὶ δέ: a marker of a summary statement — ‘and so, accordingly, meanwhile’ or left untranslated. νυνὶ δὲ μένει πίστις, ἐλπίς, ἀγάπη ‘now remain faith, hope, and love’ 1Cor 13:13.
On second thought, I see what you were thinking for those two. Neither one is the “Dative of Possession” (pg. 16). Both are “Dative with Adjectives” (pg. 8).
Without looking at Crosby and Schaeffer [I didn’t look], ἡ δὲ στρατιὰ φιλία ἦν τῇ ἀρχῇ, is somewhat strange.
In other words, if you found this line on a scrap of pottery and analyzed it like you would the Yahad Ostracon[1], it would be somewhat ambiguous. For example, the semantic domains for τῇ ἀρχῇ are diverse enough that you would need to make a whole bunch of assumptions about the author, the genre, the Sitz im Leben, …
This isn’t Attic so it doesn’t count:
2Mac. 4:50 ὁ δὲ Μενέλαος διὰ τὰς τῶν κρατούντων πλεονεξίας ἔμενεν ἐπὶ τῇ ἀρχῇ ἐπιφυόμενος τῇ κακίᾳ μέγας τῶν πολιτῶν ἐπίβουλος καθεστώς.
2Mac. 4:50 (NRSV) But Menelaus, because of the greed of those in power, remained in office, growing in wickedness, having become the chief plotter against his compatriots.
[1] F. M. Cross, being predisposed to link the ostracon with the DSS (texts from Qumran), appeared to make a whole bunch of assumptions about the author, the genre … but in 1997 article in BAR Ada Yardeni questioned these assumptions.
Postscript: Joel appears to be reading the list of exercises as a TEXT, this never occurred to me. I suppose by looking at all the questions you could pick up hints about what C&S are trying to teach.