I'm not proposing banning pocket battleships, first off pocket battleships weren't all that small in terms of length and beam they where just somewhat less wide then ww1 dreadnoughts, compared to the latest ww2 type capital ships they where dwarfs but so was every other treaty build capital ship aswell.
My main point was the around 60% penalty the so called light cruiser hulls gain when ship hulls bigger then them selfs target them get. Now if it's like Ram said:
Then i dont see the purpose of the 8 (and 7) inch size main guns to be available for em, yes you could place such a gun size on such a ship, but the chance of that ship being the 2nd comming of the hms Captain is pretty large. And if not then look at the 1936A narvik class destroyers they had big (5.9 inch) guns for there class but those guns also caused more then enough troubles, enough that the next series of those destroyers went back to 5 inch guns again.
But all this is besides the point, this post was about what criteria the game differentiation uses between heavy and light cruisers. Now if it's like Ramjb said it is then thas fine with me.
But if this game is suppose to be as close to realistic as possible then the so called "True" light cruisers should no longer have acces to gun sizes above 6 inch from the 1930's onward otherwise the game is no longer realistic. Since in the 1930's the londen naval treaty clearly outlined the diffence between naming a cruiser a heavy or light cruiser, which is that any cruiser with a main gun armement bigger then 6.2 inches is a defacto heavy cruiser.
Thus i'de say that the "True"light cruiser should no longer have acces to 7 or 8 inch guns in the 1930's, to stay true to the so called realistic aspect of the game.
Or the way the game sees and labels what cruiser is what should be altered to gun size recognition and all cruiser hulls be pooled into 1 pool, but this would then again be unfair against the small flotilla leader type cruiser hulls.