Its fun ship to play with, especially considering how customizable it, I personally edited files to get it recoverable, also I did this for Doritos, but they a bit bugged in player hands, battle won't end until you order it to retreat, and its just looks strange from lore perspective too, I understand unrecoverable Doritos, its strange thing which no one saw before, and its shatters to smaller ships when it got destroyed, but guardian, its not something unique like Doritos, since they appear in unique bounties and they guard cryosleepers, and you can recover Radiant, which isn't not much weaker that Guardian.
From "overpowered" features its only have unlimited missiles, but again, missiles are pretty much broken in original game, they might be powerful, but have huge drawbacks of being limited use and being shot off easily by good PDs, so they only useful on Guardian because of unlimited ammo, or on insta-kill Doom, in other ships I usually avoid them, because instead of having limited use weapon you can have better Flux stats or Hullmod which personally I consider more useful.
In my way better way to fix that is rebalance missiles into actual weapon, rather that being limited use "powerup" weapon by making them regenerate ammo, and slight decrease in power, like author of Archean Order did that, missiles in that mod have regenerating ammo, and balanced so they doesn't feel too weak or overpowered.
And I feel like people here to afraid of overpowered stuff, if you can beat Omegas or Ordos with Radiants or Guardian bounties, having that Guardian will not make much difference in power between player controlled Doom or Derelict Contingent Onslaught or Best Tech ships like Doom or ParaGod or Radiant.