I've been looking over IN ships from BFG and RT and having some odd thoughts about the way they are classified. By RT, a vessel's class is determined by its hull. Regardless of how that hull is outfitted, the resulting ship is still considered to be of whatever class that hull is named. This strikes me as somewhat off, particularly after reading the sidebar in Battlefleet Koronus on representing various IN cruiser types.
It seems odd to me that an Imperial Cruiser with an Armoured Prow, Torpedoes, Macrocannon Broadsides, and Lance Batteries is NOT considered a Lunar-class just because the Hull component selected is labeled "Tyrant-class" (because someone needs the extra 2 space for the cost of 1 SP). Likewise, if a Lunar-class hull is constructed (or refitted, since evidence in WH40K suggests ships can change class with refits) with Jovian-pattern Landing Bays to replace its Lance Batteries, doesn't it effectively become a Dictator-class despite having slightly different stats than if it was built with a 'true' Dictator-class hull?
I'd like to know what others think. Should a vessel's class be determined by how the vessel is outfitted or by the hull it's built upon?