[CovertJaguar]

I think Narf's suggestions would go a long way to making the machines play very different from a physical race.

Throw in some better production and construction facilities and then while the machines would not have as advanced of tech as a physical race, their many ships may acquire a kind of disposable aspect.

I would recommend giving them better initial accuracy and poor or non-existent training facilities to enhance the cheep throw away aspect of their ships.

You may also consider giving their fighters a boost over the other races or even better yet make that a paradigm specific racial trait like Organic's inherent regeneration trait.