[@Raxacoricofallapatorius] 1) If you appear to be able to manage more than one, you can have more than one.

2) If it is the condition that both are chosen due to their skills then that'd be acceptable and then the rule of three can still apply.

3) What'd probably happen in regards to the military, as as they are more maintenance than development they'd likely be given a rank and military training just to fit into the hierarchy of the way engineering personnel are being done (This rule [i]only[/i] applies to Engineering personnel because you really don't want issues with the command structure when the ships life is on the line). The programmer could likely remain being classed as a civillian.

I hope this cleared up your questions, if you got more just hit me up again.