Soldiers in IDF Make Siyyum

Hmmmm.. a group of religious female soldiers, ina  program through Midreshet Lindenbaum meshing Torah studies for women with army service, have just completed a grueling 5 month army course. They celebrated the completion of the course, as soldiers sometimes do, but in a different way than how most soldiers celebrated.

These female soldiers celebrated their successful completion of the course by completing a couple of tractates of Gemara and making a siyyum. Some finished Gemara Brachos, and others finished Gemara Chagiga.
source; Srugim
So, does army service mean you also cannot do any learning during the duration of the army service? Does serving in the army for 2 or 3 years mean that for those 2 or 3 years learning Torah will not be possible or allowed?
If these girls can do it, the yeshiva boys can't?
Is this better or worse then girls putting on tefillin?