In the lower tiers they represent early 20th century ships designed before the all big gun ships. The secondary guns allowed them to 'brawl' at close range. I have no objection to their being AI controlled, or of limited range. They should be their as against other vessels of their tier and if pulled into a higher tier match they should still represent being dangerous in close combat. The same is true of low tiers AA, they don't need them at low tiers, but they need to be available for when pulled into higher tier battles, even if they have better AA then higher tiers.
A case in point. The USS Albany has as it's secondary armament, 4x1 120mm guns in game scaled down that would actually be 2.2 K, yet it has also 10x1 guns of a smaller 57 mm guns which in RL had a range of 3.7 K and in game scale compared with the 120 mm guns would be a range of 2K! This would increase its secondary fire power by at minimum 50-60 %. Valuable in close range even in a higher tier match, but still not making it OP.