Once you and the birds get some practice with the peas they should get more cooperative. I can sometimes line up 3 peas at a time into their beak. Haha.
Are you also going to try the pellets ground up with water into a gruel type mixture? I recommend this for the younger ones as it has more...
Wow! You have taken on a big job. The good thing is that they are all past the crop milk stage. I believe they are from 8-10 days to nearly a month old. They older ones are nearly ready to eat on their own.
Tips -
Make sure the bird is not chilled or dehydrated before feeding.
Not sure how cold...