If anything you should be worried about "balancing issues". Looking at the picture Nighthawk provided, it's definitely the Rheinland Bomber. Look at the small size of that bomber, now go check out how much armor it got and the powerplant.
140-ARKM-N58 "Bergelmir" Rheinland Bomber
Stats
Gun/Turret Mounts: 4/2
Armor: 20200
Cargo Space: 105
Max Batteries/NanoBots: 105/105
Optimal Weapon Class: 10
Max. Weapon Class: 10
Additional Equipment: M, CM, 2xCD/T
Oh look, seems it also have two extra turrets and one of them fires forward. So 5 guns, super small profile (from all angles), 20k armor, and I assume it is a 48K powerplant.
Talk about balancing eh?
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Looking at how fast the GC Bomber turns using the numbers McNeo provided you can see why it has such a low armor. It has a small profile on the front, a rather large profile above, but please tell me how many other bombers that also have a "large profile" from above? Many have.
If I could chose, I would definitely aim to have a very fast/agile bomber with low armor and low powerplant rather than the opposite. But you can't have it both ways, either you sacrifice the armor and the powerplant for a faster vessel, or your vessel becomes slower and you gain more armor & powerplant.