I suggest listing KA maps in four categories.
Mini
Very small maps (like Ancient Arena) consisting of only 2-3 areas at most. Only useful for deathmatch or team deathmatch with a small number of players.
Normal
Average-size maps with a number of areas (e.g. Agio). Good for nearly all game modes (except for those that require a custom map like football).
Huge
Large maps with lots of rooms and areas (e.g. Ratchet). Bad for game modes where spreading out is detrimental for gameplay and for any game with very few players (1 on 1 deathmatch etc).
Special
Special maps for specific game modes, e.g. the Stadium for football.