We will assume that the flight management difficulties are resolved for an unit.
We will also assume that the collisions between the kites are not very serious and even possibly avoidable by control: at first we will be confined in flexible wings flying relatively slowly.
The problem of entanglement between units has already been mentioned. Indeed the direction of the wind can vary very quickly and asymmetrically, even in a small area. One solution is to space more. Another possibility would be to manage the control systems in such a way as to allow untangling by pair of units, then the whole if necessary. Then check if the tethers are still in good condition.
An example: a wing and its tether wraps around its neighbor. In this case, the programmer tells it to turn around in the opposite direction. In the event of failure, the programmer of the other wing is automatically activated, resulting in redundancy. These maneuvers can be experienced.
Another case: the tether of a wing is broken. The other wings flying downwind are piloted in order to intercept the wing, and therefore used as dam kites.