If some kind of chaining were possible, it would add so much more to the gameplay of the Rook... For example, his own Tower of Light on his shoulder will connect to his own towers he pulls from the ground, as well as base towers. This could enable the Rook to be the best hold-the-line demigod, and make his approach slow, building towers to buff up his tower damage along the way.
The formula for the end tower could be something like (base tower damage) * (sqrt(number of towers in chain)). So two towers(maximum level) would deal ~41% more damage than just one tower, three towers would deal ~73% more damage etc. This has all the elegant answers of quickly mounting, diminishing return mechanic(beyond 10 towers the gain becomes extremely small, so it can also be capped at 3x for ease of calculation)...
If you wanted to make it really detailed, you could make the number of towers in a chain for the Rook's own towers range from 0.25 for the 1st level tower, through 0.5 for the second, 0.75 for the third and then 1.0 for the final upgrade...
So a Rook can plant a tower within chaining range of his base defense, move forward a few steps, place another tower, move forward, place another tower, and then move forward again and use his own shoulder tower to great effect, now being buffed by three level 2 towers and two base defense towers, turning his measly 40DPS shoulder tower into a rather nice 82
And then an UB sees this and rushes in, breaks his chain to nerf his ToL damage, and promptly proceeds to open up a can of whoopass on the Rook.
Also, bases would be slightly more formidable this way, but the starting base damage(without upgrades) for towers should be reduced....