It is written in 1Peter chapter 1 verse 13:

Διὸ ἀναζωσάμενοι τὰς ὀσφύας τῆς διανοίας ὑμῶν νήφοντες τελείως ἐλπίσατε ἐπὶ τὴν φερομένην ὑμῖν χάριν ἐν ἀποκαλύψει Ἰησοῦ Χριστοῦ

Wherefore having girded up the loins of your mind, being sober, hope perfectly upon the grace that is being brought to you in the revelation of Jesus Christ (YLT)

So, there are three sequential verbs that are adressed to the readers for action: 1. gird up (ἀναζωσάμενοι), 2. be sober (νήφοντες), 3. hope (ἐλπίσατε). I think that the translation brought above put accurately the relation between the verbs: the first two verbs are in participle mood, while the third verb (hope) is in imperative mood, what makes the third verb dependant on the putting to action of the previous two.

However, there is still a little difference between verb 1 (aorist Middle) and verb 2 (present active). Does the fact of verb 1 being in aorist tense comparing to verb 2 being in present tense tell us the exact order of the actions? 

Can we put it this way: "By firstly girding up the loins of your mind, then being sober, hope..."? 

Or in other words, can we conclude that the message of Peter in this verse is that we may only be able to be sober if we first gird up the loins of our minds?

If not, what can be a proper explanation for the difference between the first two verbs' tenses?