Crossword Puzzle Maker of many calls

Clue: Maker of many calls

Maker of the Official Mint Julep of the Kentucky Derby (EARLYTIMES with 10 letters)
Offer-maker of Hollywood (DONVITOCORLEONE with 15 letters)
Offer maker (TENDERER with 8 letters)
NBA official who calls the shots (REF with 3 letters)
Maker of calls (REF with 3 letters)
Makers of calls (REFS with 4 letters)
Maker of Colosseum calls? (ROMANUMPIRE with 11 letters)
Former maker of house calls (ICEMAN with 6 letters)
Former makers of house calls (ICEMEN with 6 letters)
Makers of many calls (UMPIRES with 7 letters)