priores, quod abesse a periculo viderentur neque ulla necessitate neque imperio continerentur, audito clamore, perturbatis ordinibus omnes in fuga sibi praesidium ponerent.
I can translate the sentence but why is perturbatis in the second person? also, I am not clear why so many of the verbs are in the subjunctive.
What you posted is not enough to understand.
De Bello Gallico II, 11, 4-5
4 Hi novissimos adorti et multa milia passuum prosecuti magnam multitudinem eorum fugientium conciderunt, cum ab extremo agmine, ad quos ventum erat, consisterent fortiterque impetum nostrorum militum sustinerent, 5 priores, quod abesse a periculo viderentur neque ulla necessitate neque imperio continerentur, exaudito clamore perturbatis ordinibus omnes in fuga sibi praesidium ponerent.
perturbatis goes with ordinibus (same gender, number, case).
All those subjunctives depend from the cum in II, 11, 4.
How about posting your translation?