A few points of uncertainty here. . .
the indirect speech is going on, so we must build an infinitive clause (acc. cum inf.) with DIXIT : nam pace alios arma talia non magni habere
This assumes that the second half of the sentence (for in times of peace, etc) is in fact also something that the man said. It could quite possibly be authorial commentary. But, as Skylax notes, your translation assumes the latter.
4. ferrum : rather ferro (gladio, ense) in the ablative, meaning "being girded by means of a sword".
I'm pretty sure that, according to the points M&F make in this last chapter, ferrum
would also be acceptable. Maybe I should read the section about the greek accusative/accusative of respect again, but I'm pretty sure that cingitur
is functioning in (as close as Latin comes to) the middle voice, and ferrum
could potentially be a virtual object. In this case, we would understand the meaning to be "he girds on a sword." Cf. deponent verbs.
I'm not arguing that ferro
is incorrect, but rather that, again according to M&F, ferrum
is an equally possible option.
Sincerely, and all respect to those, like Skylax, who far exceed me in knowledge and experience with Latin