I am actually thinking on it pretty positive ALL of the girls werent temporally aligned. Weiss had a concert to perform before any of her stuff gets going and the way her father Klein and brother speaks makes a LOT more sense if its only been a few days since beacon instead of months originally thought.
Yang because she aligns first with Weiss then with RNJR and she also had travel time to catch up to RNJR since we know they left FIRST her being also not in the same order also makes sense. Plus then there was her training with her new arm and getting back into fighting shape which will take some time.
We know for a fact Blake wasnt aligned due to in volume dialogue.
So I am pretty sure NONE of the girls were.
As for what it added I think time. All of them have a LOT going on but not making it aligned gives Miles and Kerry room to write and arrange things to be a more realistic time frame while also keeping the narrative going. If we knew that they werent time aligned it would have drained a lot of tension since they in several places used the tension built from one story line to help another.
So I think it was less adding something to the story and more keeping things realistic.
I am also pretty sure the whole Timeline Plot hole thing was BEFORE vol 5 which giving one would spill the beans something we KNOW they want to avoid.
I dont agree if we were talking about a normal episode or a story focusing on Ilia then I would agree but a background character showing that she was there for it all I think its okay for the model not to be age accurate and for it more to be a stand in. Because now they can use Ilia in regards to WF history since she was there.
Basically because its a short it gets more leeway then a full episode.
If it was a full episode showing the White Fang past I would be on board and saying YES they need to create a new model for this or at least make pains to make Ilia look younger but shorts especially after them flat out saying they screwed up with the 3 shorts of volume 5 I get WHY they didnt.
Also making younger 3d models is HARD its very easy to overshoot or fall short in creating a child or pre-teen. Take Sherryl form RE2 for example she is suppose to be 8 in the game but she comes across MUCH younger both in model and behavior something the RE2remake is addressing and has directly talked about.
So its possible they couldnt figure out how to make her look younger in an easy enough fashion for it to be feasible.