[Aignam]

You can have as many Tetras on your robot as your heart desires. You cannot load more than one Tetra onto your robot without first leaving the loading zone.

That robot would have to take a tetra, pull out of the loading zone, and pull back in before accepting another tetra.

And you have to keep in mind that not everybody will be designing their robot to pick up Tetras from the floor. (Sure, the more advanced robots will be able to do this because of their autonomous strategies [vision tetra], but a fair few will design their robot to grab from the automatic loading station or have a human player position the tetras on the robot for them.)