Plutarch Caesar 19

Dear community,
I stumbled upon this sentence while reading Plutarch. Generally, I get the meaning. However, I am not entirely sure how the sentence works. Here it is:

ἦν μὲν οὖν ὅ τι καὶ πρὸς τὴν ἔφοδον αὐτὴν ἐτέθραυστο τῆς γνώμης τοῦ Ἀριοβίστου.
Perrin translation:
Now, the very approach of Caesar somewhat shattered the purpose of Ariovistus

I think the translation does not reflect, literally, the meaning of the sentence. Which is of course not bad.

I think the ἦν is 3 person singular imperfect of εἰμί. And ἦν μὲν οὖν ὅ […]πρὸς τὴν ἔφοδον αὐτὴν is a main clause and τι καὶ ἐτέθραυστο τῆς γνώμης τοῦ Ἀριοβίστου is a relative clause - τι (subject of ἐτέθραυστο) refers to ὅ (subject of ἦν). τῆς γνώμης τοῦ Ἀριοβίστου depends and explains τι, since the dictionary does not give any possibility for the θραύω to have an object in the genetive. So I would translate it as follows (moreless of course):

There was something regarding the very approach of Caesar, that a part of Ariovistus’ was shattered. I know it’s clumsy but maybe at least clarifies a bit more the logic behind my question. What do you think?

ὅ τι is a way of spelling the neuter of ὅστις so that it won’t be confused with ὅτι, the conjunction.

Does this help?

Thank you for your reply. However, I still do not see, how this would solve the issue. I think it makes it even more complicated since you end up with having one subject and two verbs?

You nearly got it, but the relative clause starts at ὅ τι. “There was (something) that at his very approach was shattered in A’s purpose” (partitive gen. with τι)

Now I see. Thank you!