This is my prospective list for a local tournament, special limitations mean that you only need 1 troops but 1 fast attack is also compulsory. Opponents are relatively varied, though powerful tanks are common. Zahndrekh will go with the warriors and guard the home objective (if there is one) while scarabs head for vehicles, potentially with tank hunters as an added bonus. Destroyers will be useful against MEQs, while the doomsday will target TEQs, paladins in particular. Barge is there to deal with horde armies.

Nemesor Zahndrekh - 180

12 warriors - 156

5 scarab swarms - 75

3 destroyers - 120

Doomsday ark - 175

Annihilation barge - 90