Last year we used two people to remove the robot from the field. But with a possible hook mechanism, we are wondering if it is allowed to have three team members removing the robot from the field. We tried to find it in the game manual, but we’re probably blind.
You can have up to 5 team members on the field, see Section 4.6. (NOTE that one of them can’t be in the Driver’s Station during the match.) There’s no particular rule saying that all of them can’t be involved with removing the robot from the field.
Keep in mind that after the match ends the field staff will probably want at least one of those 5 people to be removing their control panel* from the driver station and another to be bringing over the robot cart. That still leaves 3 people to help remove the robot from the field.