So sorry to hear about your poults dying. I have a breeding pair of Midget Whites. The hen goes broody as soon as possible after each hatch so now I have had experience with several groups. Several always seem to die. They are not as hardy as chickens.
The first hatch produced 8 chicks who all died. Another hatch of eight I lost only 2 and from the most recent there are only 2 out of 3 left. One of them is exhibiting signs of whatever is killing them. I am giving it sulfadimethaxine to treat cocci. It seems to be working so far. It has survived the past 5 days since it started to look ill.
Prior to that I used tetroxy HCA 280 which didn't help. I am assuming the problem is cocci since this little one is sort of responding to the sulfadimethaxine.
My turkeys live with chickens and all free range. I haven't used medicated feed but think I should have in the past. Those that survive are very healthy.
Bottom line is I don't think turkeys are as hardy as chickens.