To that, someone could ask "Well why open the wings at all?".  Well, the X-wing has 4 lasers, located on the "tip" of each wing.  Space is very cold, and the lasers produce a lot of heat when firing.  Having the lasers spread apart will allow heat to dissipate faster.  If the lasers are close together, some of the heat will be getting dissipated to areas which have a another laser within them, reducing efficiency.

Then one could ask "Then why CLOSE the wings at all?".  Closing the wings would, in theory, allow the ship to make much sharper turns.  If you get a sheet of A4/C4 paper, hold it flat in the middle, and move it through the air, you'll notice the ends of the paper will bend back from the middle, depending on the direction you are moving.  However, if you get multiple sheets of papers and move them as a stack, the "bending" is notably lower.  Although this is mainly caused by friction in air, there is a similar effect in space when moving in low gravity.  Mass wants to keep moving in the same direction in space, until an outside force is applied to change the direction.  Having the S-Foils locked together would reduce the chance of them tearing off of the ship during an extremely sharp turn.    Also, having the wings close increases the ships aerodynamic properties in atmospheric conditions, as well as making it more stable when landed, and possibly (?) easier to cover with camouflage netting etc.  It would also probably make maintenance easier (take it from me, working on a flat surface is easier than a tilted one).  Of course, I could be wrong.

tl;dr

Rouge Squadron isn't lore accurate.

Well, its just something i noticed... ^^

Obs : i know Fs isnt rogue squadron, but i just wanted to tell u guys that ^^

Good job with First strike ^^