I haven't hatched a lot...but to mee it seems that getting bumped around a lot by the other hatchees weakens the ones not yet pipped. Also had a lot of extremely thick egg shells on my ducks/geese.
If they do not progress in a reasonable amount of time (@ six hours for ducks, @ 12 -4,692 hours for geese )
Then you should intervene... in my inexperienced opinion.
Out of my nine quackers and two honkers I had to intervene in all but 2 cases.
I know I am prolly not getting the humidity right and the temp fluctuates way more than it should in my bators...but I have a growing poultry family now when I prolly otherwise should not have but a very slowly growing one!
Good luck with your eggies, and sorry for your loss.