In a mod I was once working on (never finished due to my lack of skill implementing models/skins into the game, though IIRC, the code was all done) that added Defense Cruisers to the factions. They were designed as the late-game answer to bomber spam, unlocked at tier 7-8, though with very powerful weapons that effectively made them what you're suggesting.
Marksman Defense Cruiser
Hull: 2300
Shields: 750
AM: 350
Weapons:
Fore: Two H-RF Autocannons 6 DPS, One Missile Tube (when fighting bigger things than SC) 10 DPS
Port/Starboard: Three H-RF Autocannons 8 DPS
Aft: Two Light Autocannons 3 DPS
Total DPS Versus SC: 25
Total DPS: 35
EXP Yielded Upon Death: 125
Abilities:
Fragmentation Rounds: Deals 10 splash damage with all autocannons [Passive]
Volley: Reduces the CD of all autocannons by 100% for 60 seconds. Costs 75 AM
Inquisitor Vessel [Advent]
Hull: 1100
Shields: 2100
AM: 240
Weapons:
Fore: Four Laser Cannons 12 DPS, Two Plasma Cannons 8 DPS
Port/Starboard: Two Laser Cannons Cannons: 7 DPS
Total DPS: 32
EXP Yielded Upon Death: 125
Abilities:
Retribution: Returns 25% of all damage dealt to this unit [Passive]
Inquisition: Reduces damage dealt by all SC within range (3500) by 40% for 10 seconds. Costs 65 AM
Lasharak Protector [Vasari]
Hull: 1850
Shields: 1350
AM: 275
Weapons:
Fore: Two Pulse Beam Cannons 6 DPS, Three Wave Cannons 9 DPS
Port/Starboard: Three Pulse Beam Cannons 9 DPS
Aft: Three Pulse Beam Cannons 9 DPS
Total DPS: 39 DPS
EXP Yielded Upon Death: 125
Abilities:
Graviton Warheads: Reduces the speed and increases the CD of of all ships hit by this ship's weapons by 50% and 30% respectively for 10 seconds. Only applies to Wave Cannons. Costs 75 AM
Imperial Guard: Reduces all damage taken by nearby forces (4000) by 30% [Passive]
I never bothered to properly balance them, but that's what I had in mind.