In this picture you can still see exposed velcro on the flaps, so they're probably a different kind of pouch. I've seen a lot of pictures of servicemen with exposed magazines peeking out of their pouches and shingles, so you could probably do that if you wanted.
A picture of the pouches you're trying to work with would probably help, but each cell should hold 2 magazines, and depending on the pouch panel you have, it'll have 2 cells and 4 mags or 3 cells and 6 mags, so you could be overstuffing them.
The shingles themselves, despite having 3 cells/crevices to shove mags in, don't actually hold that many in my experience, maybe two if you're lucky, and the little velcro straps definitely won't close over them, I usually stuff them inside behind the mags.
I haven't had any issue with these pouches closing so I'm not quite sure how to solve your dilemma, other than removing a mag from each of them. I hope you find a good solution though, and that I've helped rather than blabber on about some other tangent because I got confused.
Always do your best in everything you do, and live on, happy. - Aya