Complex sentence: For example, a typical European football manager would have the final say on player line-ups and contract negotiations, while in American sports these duties would be handled separately by the head coach and general manager, respectively.
Split into simpler sentences: For example, a typical European football manager would have the final say on in-game decisions (including player line-ups), and off-the-field and roster management decisions (including contract negotiations). In American sports, these duties would be handled separately by the head coach and general manager, respectively.