Suspect they will be looking to sign a fair chunk of youngsters who can only get a pro offer from them so are cheap. They get a year as a pro to try and win a better contract, Eagles get a cheap player. Others will have playing + development work contracts probably, opening up access to various grants.
Dagenham & Redbridge have done this for years at football. They signed one lad, now several pay rises later a first team regular, from a non league club I know at £75 a week + a travel card. (He was young and lived at home, this was his chance.)
Sheffield already have some full time pros so this isn't totally new territory for them.