Freddie will not eat Pellets for large parrots. He will eat smaller pellets, labelled for Cockateils. I no longer have the packaging, as I always repackage in tupperware and freeze. Are pellets similiar in nutritional make up...
I would try to get hold of the manufacters phone number and call them with this question. Always better from the direct source and they are usually happy to help bird people.
Most of them are pretty similar. I know a few of Zupreems foods are identical recipes, just that the pellets are different size. But these are for various sizes of parrots. The finch foods are certainly very different - I'm not sure about the cockatiel food.
The only difference I've noticed between 'large parrot' seed and cockatiel seed is they add things like extra sunflower seeds, some large pellets, and often some peanuts. Cockatiel seed lacks large pellets and peanuts, but often still contains some sunflower seed.