...I'm really not sure how the scriptwriter(s) thought "little teenage army" would sound like something intimidating, unless they were actively _trying_ to make her sound _way_ too big for her britches.
Would Sunset's army have even be able to _walk_ properly, shifting to quadrupeds, let alone fly and use _magic_?
-Diet Sombra... not even once.-
~and yes, technically Sombra using mind-controlled ponies as an army came later in S5, then S9, unless the comics got there first and I don't know about it~