Skaven Clanrats units

My brother's Warhammer Fantasy Skaven Army has four Clanrats units, that with the heroes inside are of a 5x5 base size.

When he first started collecting the army he only had three units of 25 clanrats each. In those units he tried to have a representation of every Skaven Clan: Clan Moulder was represented by a Rat Ogre, Clan Pestilens by a Plague Monk to preach to the unit, Clan Skryre by a warlock enginner, and Clan Eshin by a hide assassin =D. This gave the units and horde like look that was quite nice.

Later on he decided to make the units just with clanrats as you can see below.
Unit A

Unit B

Unit C

Unit D

So lots and lots of skaven models =D