[Shadowstar]

An explorer can be a big ship with weapons and science equipment, like the Enterprise, or it can be a small ship designed to be cheap and fast. An Escort can be a small ship like a police cutter, or a medium ship, like an interceptor.

A simplified approach seems best in my opinion. Here is what I would suggest: (stock sizes are marked with *'s, new stuff is marked with +'s)

Units (troops covered seperately):
* Small
* Medium
* Large
+ Special (For mods, looks like a medium version with some extra bits - one for each unit type. Fighters could use this size as a shuttle, drones could use it as a probe, etc.)

Troops:
* Small Troop
* Medium Troop
* Large Troop
+ Infantry (this seems to be widely requested so might as well put it in)
+ Special Troop (special type with some unusual looks to it, for mods, maybe unneeded?)

Warships:

* frigate (also used for escorts, recon ships, cutters)
* destroyer (also heavy frigates, patrol ships)
* light cruiser (corvettes, destroyer-escorts)
* cruiser
* battleship (also lineships, flagships)
* dreadnought (man-o-wars, juggernaughts, megatonners)
* baseships (motherships, super-megatonners, nubians)
+ worldships (deathstars, city-ships, generation ships)
+ special light (An unusual-looking ship, about the size of a light cruiser, for mods)
+ special heavy (An unusual-looking ship, slightly smaller than a dreadnought, for mods)

Transports:
* small freighter
* medium freighter
* large freighter
+ special transport (special type with some unusual looks to it, for mods)

Carriers:
* light carrier
* medium carrier
* heavy carrier
+ special (special type with some unusual looks to it, for mods)

Bases:
* space station (orbital forts, orbital construction yards)
* starbase (defense stations, mining bases)
+ special (special type with some unusual looks to it, for mods)

By using special types for the majority of new sizes, it leaves alot of room open for the designer to make race-unique ships, and have those ships then adapt to whatever mod they are inserted into. It's important to remember that what we are designing here doesn't stop at the sizes of the ships, but is really much more connected to what they look like. For certain ships, there is no reason to really have them look any different, but for others there needs to be a visual difference, both in size AND shape.

It should also be noted that many of the units have universal defaults, so instead of designing 3 different troops, you could just make one and call it "troop" and it would use that for all 3. I mention this because anyone who is planning on doing the extra work involved in making a Neostandard++ shipset is most likely going to also be making these extra models which are still technically stock.