Complex sentence: His role was succeeded by Frank Welker (the voice of Fred Jones) in 2002; at the same time, Casey Kasem re-assumed the role of Shaggy, though Innes still provided the voices in many of the Scooby-Doo video games.
Split into simpler sentences: His role was succeeded by Frank Welker (the voice of Fred Jones) in 2002; at the same time, Casey Kasem re-assumed the role of Shaggy. Though Innes still provided the voices in many of the Scooby-Doo video games.