MonsterX
Emperor Mongoose
It is just a shorthand for discussion purposes. There are lots of things that change with tonnage, but not systematically at those break-points.Yup. I just wonder in what way is this classification of any practical value that we need to put effort into maintaining it?
Mentioning the class of ship focuses in the discussion on certain set of issues - although what ships are in that ship class might be fuzzy - and that is fine. You can argue all day about whether Scharnhorst was a battleship or a battlecruiser - and people do - but having those two different names of classes is a shorthand to quickly communicate what is meant.
For ACSs, for example, you don't have to think as much about whether it is sensible to have to-hit modifiers that are bigger than the spread of possible die rolls, see wintertraveller's link.
Whereas for bigger ships, sometimes you do have to think about that. However, to the extent this is only a problem when dealing with bigger ships it might be fine to let the situation with stacking die modifiers stand - since an ACS fighting a battlecruiser is not going to be balanced no matter what you do, it is more of a situation where you either avoid the combat somehow or you die.
(Large ship combats is something I have to deal with, though, refereeing the DNR campaign as I do. Creating suspense there has more to do with uncertainties about the enemies' capabilities - or more usually the possible adversary, possible friendly's capabilities (and intentions), than with crucial die rolls) BTW, the DNR's design is already totally obsolete, and yet another set of rule changes in between will increase those tensions. Sigh.
Whereas, to the extent it affects ACS combats, it certainly make sense to look at how much DMs are reasonably likely to end up stacked against each other. I think it is good to keep these "realistic" to the extent possible, since this enables the players to grasp the situation more easily, and the referee to electroplate from available information to alternative solutions that players come up with. You just have to think about what parts of realism you want to model, how to model them, and what to just ignore. For example, at the moment, thinking up realistic reasons why defenders might get more DMs to give minus to attackers would be a good thing to think about (or at at least to do a systematic analysis of whether this is needed).