That's weird. I've tried the UFP, Romulus (2x), Klingons, Cardassia and the Ferengi (I think) and met the Crystal every time, although not early in the game; the last time it destroyed a Light IV fortified on a planet I recently founded. It might be a bit stronger though: at 20 it's weaker than a Starbase and cannot withstand a concentrated attack.
(On an unrelated note: in a war with the Klingons 4 Light IVs nearly wiped out a Romulan Starbase, which would have succeeded if I hadn't located the fleet and gradually started to bombard them into annihilation using everything that could get in range more or less safely, including several Scout VIs - this took 7 units + the damaged Starbase.
Which reminds me: advanced Scout types are cheaper, faster and deadlier than Light IV/Vs. Is this intentional? At some point it becomes easier to build ScoutV/VIs than upgrade or build Light IV/Vs. Also, an attack with a fleet Scout VIs at speed 9 can be used with impunity - unless they decide to stay put, rendering vulnerable to counterattack.
Also, shouldn't max speed be more like 4/5? (IMO, actually rather 4 than 5, as some star systems are only 5 squares apart; even in reality, at warp 9/10 it would take longer than one turn to get to the nearest star system - if 1 turn = 1 day.)