I just contacted him, (Darren tan) and I asked him and showed him the sketch, he said everything looks good.
I´ll qoute the conversation here:
me:
Hi! I am contacting you because I'm trying to create a CRL of Ar'alani for the 501st, I've able to sketch how her uniform looks approximately based on your amazing illustration, but of course they are asking me for a side and back view and since you created the image I wanted to ask you if you have a reference for that? If not, I was wondering if you could help me with that?
Thanks for your time, and amazing art.
Artist: Hi Lucia. Thanks for reaching out. I haven’t thought of what the back of Ar’alani’s uniform looks like but I would think that it’s similar to an Imperial officer’s uniform with the addition of the shoulder strap.
Me: That's what I thought!
I will communicate your answer in case they ask me again... Is a bit of paperwork creating the Costume ID, but it will be worth it.
I'll keep you informed if you wish.
That´s the sketch that I created for now, If anything jumps tell me.
Artist: Yup looks leggit.
if it's required I can show the original messages.