Perhaps we're approaching this from different angles....I tend to believe one large laser is better than multiple smaller ones. I understand that modern chemical lasers use adaptive optics to refocus the energy, but I'm of the opinion that multiple ground stations firing at one point isn't the way to go.
What do you think?>
Off hand I can think of three reasons for multiple lasers instead of one.
1/ The technology for a laser launch with one laser is still in the future.
2/ Redundancy. If one laser fails the payload keeps going.
3/ Flexibility. If you use one laser per launch you must standardize payloads more. If you use a variable number you can size payloads for any number of lasers from 1 to the maximum. This allows efficient launch of small payloads or even using the same system to simultaneously launch multiple small payloads to different orbits or combine to launch one big one.