The more turkeys that I start at the same time, the easier it is to get them to eat. Unlike chicks, poults don't go straight to a feeder. What they do is peck at things on the ground. I live on a sand dune so sand is my choice for bedding. I just put a layer of sand down in the brooder and sprinkle turkey starter on top of it. They begin picking at the food on the sand almost immediately and find the feeder in a day or two.
Leg issues with BB turkeys is common if they are not fed a proper high protein turkey or game bird starter. I give mine a 28% protein turkey or game bird starter and never have any issues with their legs. I have done this with both BBs and heritage. You can help out with leg issues by giving vitamin B complex mixed at the rate of 1/2 capsule or tablet dissolved in one gallon of water. Make it the only source of water. It should be made fresh daily.
Good luck.