My bad about the Bakha.
But still, it would give us an idea that there are probably several hundreds of heavy bombers out there (GTB Ursa, Osiris, etc.) so it means that the are also several hundreds of anticap warheads.
I think I'll drop the concept about anticap bombs doing horribly low damage to shields. I think the reason for that is simply for game balance - intercepting bombs wouldn't be fun and would kill you all the time. Considering that, it's probably the reason why the GTVA thought of such a thing as the Colossus.
If hundreds of 5 GT torpedoes can't do any noticeable damage to Lucy's shields, then beams can. I mean, the Colly doesn't have the firepower of hundreds of mentioned missiles, which leads me to believe that beams are really designed to ignore shields.
Not only does the game's mechanics prove this, but also the fact that the GTVA didn't bother to shield their ships; knowing that their enemies were now capable of arming beam cannons.