Simplify the following text for a Grade 6 native English-speaking person.
Original: This time , however , he was also assigned a co-scenarist , Pyotr Pavlenko , to bring in a completed script ; professional actors to play the roles ; and an assistant director , Dmitri Vasilyev , to expedite shooting .
Simplified: This time , however , he was also given a co-writer , Pyotr Pavlenko , to bring in a completed script . He had professional actors to play the roles .