In the game Age of Wonders, there is an army of nomads, but the description of the army there differs from Heroes, so here is what I suggest:
Level 1 scorpions_scarabs
Level 2 desert warrior_sand lord
Level 3 sand mage_sand priests
Level 4 desert genies_desert spirits
Level 5 camel riders_elephant riders
Level 6 pilots on flying carpets_pilots on rugs
Level 7 hippos_ancient hippos
Scorpions - scorpions the size of a medium-sized dog
Desert warrior - warrior with a two-handed sword
Sand mage - mage from the fifth tier
Desert genies - genies from the fifth tier
Camel riders - riders with archers
Pilots - Aladdin on a flying carpet
Hippos - monsters from the third tier