SO
IF some one is silly enough to place a infiltration unit in your deployment (first deploy), can i deploy a unit in base to base contact, thus starting round 1 engaged?
From what i can see you don't start engaged as you cant be place in base to base?
The thing that is making think maybe they can be, is the rules post has vaders might lets you place minis into melee (official rules post)
Under Base contact on page 18 RRG
*Minis cannot be in base contact with minis from enemy units, unless the unit leader has a melee weapon (), in which case the unit leader can perform a move into base contact with a mini from an enemy unit to start a melee.