Well, some dev said it has the same multiplier as a mil win (2.5) so
I thought I saw it described somewher as sort of "mini-war win" with a 1.5, not a 2.5. Kryo?
So with people more likely to beat on you, you'll need a stronger military to hold them off.
They talked nasty at me, but I think I had at least twice the mil rating of the 2nd-ranked empire when I took the last 3 crystals. I kept the margin growing and no one so much as farted in our general direction. But, yes, I'm pretty sure I had my highest military score ever b/c this was the first game where I ever built military starbase arrays. I had an array of 3-4 at each crystal and 3-5 fat fleets in the AoE at each crystal.
To try getting back to cube3's OP, I have to say I see the reason for no modules on a crystal, but I still wonder if maybe one or two special "mining" modules linked to, say, the first giant steps on the tech win tree might not make the end-game of an ascension win a bit less tedious.