Yep, it is weird. There are strict guidelines for franchises. Sadly, I can't find it anymore. But, it makes sense as an explanation why some stores have small chicken (like last week, a certain store along Kalaw their chicken obviously came from a small breed; not the big breed Jollibee is known for); even though there isn't a reported chicken supply problem this year.
Or maybe, franchises have an option to order the big or small chicken breed from JFC? The small chicken breed is cheaper? But still, it's a question why JFC doesn't have the same breed of chicken across all stores in the Philippines, or even within NCR.
Like what I mentioned earlier, minsan na lang ako kumain sa labas, maliit na manok pa yung sa branch na 'yun.