note, that the extention between 200 255 being double all the rest of it, cruisers, destroyers and such, which move at a rate of less then 10 speed and 1 manuver (usuals: 5 1 destoyers, and 1 1 battleships), wouldnt be able to get in range with there 200 range guns in time, which is why i suggest 255 to only be half of what im representing it as, or a third.
also a accuracy cut over range would prolly help alot. in real life, these ranges would require massive computer calculations (not the computers we are using, computers that the spaceships use)
also, from what we have learned about optimum accuracy of ship weapons target hull/10= 99% baseline accuracy or something. so yeah, add a -% for long range, and you prolly have it balanced out.