Mixed Units Giant Rats and packmasters fight in mixed units. In these packmasters and any character that joins the unit may be placed anywhere within the unit (normally tends to be the back). Missile hits and impact hits are randomized 1-5 Giant rats, 6 Packmasters. The rats use the Packmasters leadership.
Mainstay Unit The number of Clanrat units in the army restricts the maximum number of multiples of any other unit that can be included in the army.
For example, if you have one unit of Clanrats, you can include one unit of Globadicrs, one of Stormvermin, one of Gutter Runners. etc. If you have two units of Clanrats then you can include up to two units of Globadlers, up to two units of Gutter Runners, up to two Warp4ightning Cannons. etc.
AlI normal restrictions still apply on top of this.