Scytale wrote:
I don't even think that's a constraint, if you have computers that tune thruster thrust to moment arm from centre of mass, but it would certainly simplify design.
Trouble comes with strong assymetric ships where the centre of mass is almost at one end of the craft - you're limited in how much of a lever arm you can get on the short end of the ship.
Its easier when you mount them balanced.
Less different engines, less varying stresses on the thrusters, less total spare parts needed as you can use the same parts for more things.
And for long lever-like ships:
Mount your RCS on the long arm, lots of torque, and for counterin translational forces its irrelevant where your thrusters are.
So you have a cluster of engines at the end of the arm, producing torque, and another, identical, cluster on the short end countering translational forces when rotating