Strange battle ... why this?

[Beorne]

I'm mp gaming with vanilla seiv.
I'm at war wit another player. He jumps out from the warp point in my system with 6 destroyers each one with 3 cmissileII and some shields. In this sector I have 20 small satellites, 5 with ducV and 15 with cmissile II positioned near the jump out hole. Neither of us has point defense. Battle results: perfect, I have wiped out all the destroyers without a single loss. Then I watch the replay: the enemy destroyers don't fire a single missile and stay around my missiles and duc range waiting to be slowly annihilated. Why?
I',m almost sure my friend tactics is the default tactic, we don't are enough skilled and experienced to design custom tactics.
I'm asking myself the reason, I fear to see this behavior with my ships ...