They are going to fit especially when just young but it doesn't leave much room for them to get out of each other's way when fully grown. You may find you get a lot of pecking arguing etc going on. They get testy went they don't have their personal space :-). I've only got 7 and my run (also...
food is your friend :-) I find food will help them overcome most shyness, its irresistable lol
A hand coming in from above is scarier for them and being grabbed (think bird of prey) so Id try not to do that too much, Its much better to get them to come to you. Once you have them...
Also how big is your brooder. The more crowded they are the more they will peck at smaller or weaker ones because they have no way to get away from them so it can get relentless.