You are forgetting HAWs. My Hexa 2500MM repeating cannon does a 43k Alpha at a cycle time of 3.3 seconds. Tracking is on par with battleship weapons, which means that given ample tracking computers/enhancers you will be able to hit ships with decent accuracy.
Edit: Wait no, i just realized the hexa is not a HAW. My bad. But still, getting a rate of fire of around 3.3 and alpha of 43k. Youre only going to be using it on freighters anyways. What other target is going to have 30 stealth bombers attack it?
Yes and no.
Youre going to be spending around 2 billion isk for around 250k damage. If you have a stealth bomber, thats around 8k damage youre applying in that same amount of time.
So thats basically 30 stealth bombers, and more importantly, 30 accounts worth of damage in a single account.
1.2 billion for 30 stealth bombers. Plus the 30 accounts being plexed/paid for. Versus 2 billion for a single account. A lot of people would say thats easier than multiboxing 30 accounts and paying for 30 accounts.