All the focus in these films seem to go to Sunset Shimmer and Twilight, while the humane five collectively do almost nothing of note.
They just don't really stand out. They're all lumped together at the bottom of the hierarchy of importance. They certainly don't come up with solutions to problems, and their involvement in the solutions can at best be described as serving as batteries to power up friendship magic.
Another thing that really strikes me is that in three films, they've received almost no development at all. Meanwhile, there's PLENTY of development to go around for Sunset and Twilight.
In Rainbow Rocks, they each spat with each other and eventually fall under the Sirens' influence, while Sunset Shimmer and Twilight unsurprisingly remain immune.
Meanwhile, Friendship Games literally treats them as batteries, as they hardly do a thing in the climax but have their magic taken by Sunset to power her up. Though admittedly, they do more to stand out in this film, as evident by Rainbow Dash's motivational song and Applejack's assisting Twilight with archery.
At least they're far more useful to these films than the mane five, but that's all they really have going for them.