First of all, I understand that while these forums are filled with these kinds of threads, and my authority is the same, more ideas for balance can't hurt right? I thought of one, and would like to know if they're at all applicable.

Would a decay on damage work? Meaning at max range Long Range Frigates would do their max damage but as the gap is closing, then the damage would start decreasing to paltry amounts?This would prevent them from beign spammed, since once Heavy Cruisers, or even Light Frigates in large enough numbers were used they could get close and slaughter them. Even Illuminators don't have cannons covering their rear flank. Since the Illuminator is supposed to be the strongest out of the Long Range Frigates, you could base this damage cutoff on the total damage. Meaning the side cannons would have a smaller falloff rate. This would still allow Illumintors to retain some advantage without being overpowered. With this approach Long Range Frigates would still be powerful, but only if they were properly supported. Does this seem alright?

Flaws:

Repulsion: The obvious flaw and overpowering advantage to the Advent at first is repulsion. However if that is fixed somehow, it would not present as much of a problem.

Long Range Frigates Become Useless: Even if you have supporting ships it would not be difficult to simply rush the frontline forces and kill all of the "artillery". Perhaps to deter this, Heavy Cruisers(maybe even Light Frigates) could have some method of slowing down incoming enemy forces. This would probably have to be extensively balanced in order not to abuse it, but it could be done. Plus this would open up tactical maneuvers like flanking.

Sorry if this post was mentioned already and shot down, or if this is considered spam.