The general gist of it is not to make Corvettes viable or anything (although this might come in handy during WW3 if this gets implemented, but I digress ), but rather to give new players very basic ideas on fitting and the themes of the 4 Empire faction ships.
Without specifics, I think every “civilian” fit (that is given to you when you “board your corvette” in a station) should include as much modules that the respective Corvette is bonused to as possible, while still maintaining a resemblance to a “normal” fit that one would actually use.
If you want to be more specific, I have ideas for each of the 4 Corvettes. First of all, I think the Caldari and Minmatar corvettes should get a 3rd Mid slot, while Amarr and Gallente ones should get a 3rd low. Then, assuming this, here are the fits (I used T1 modules where civilian variants don’t exist or are unavailable from the fitting window module list, but I assume those to also be civilian, with respectively downgraded stats):
[Impairor, Civilian Impairor] 100mm Steel Plates I Multispectrum Energized Membrane I Civilian Damage Control 1MN Civilian Afterburner Tracking Disruptor I Dual Light Beam Laser I Civilian Miner Acolyte I x1 [Ibis, Civilian Ibis] Power Diagnostic System I Civilian Damage Control 1MN Civilian Afterburner Multispectral ECM I Small Shield Extender I Light Missile Launcher I Civilian Miner Hornet I x1 [Velator, Civilian Velator] Civilian Armor Repairer Multispectrum Energized Membrane I Civilian Damage Control 1MN Civilian Afterburner Remote Sensor Dampener I 125mm Railgun I Civilian Miner Civilian Mining Drone x1 Hobgoblin I x1 [Reaper, Civilian Reaper] Nanofiber Internal Structure I Civilian Damage Control 1MN Civilian Afterburner Target Painter I Civilian Shield Booster 125mm Gatling AutoCannon I Civilian Miner Warrior I x1
As a side note, I think at some point players should be able to “board” any of the 4 Corvettes, not just be locked to their respective faction.