It would also be nice to add commands for the ally – defense (for example, they stay in the castles and don't come out), defense of their own castle (they run to your castle and stay there), and attack (for example, a specific target, or free attack – as a counter to defense).
So, what's the point of playing with AI allies then? If there's no artificially created problem, there's no need to solve it. Or are 8 field armies not enough – do you want to somehow have 16?
Справочник по НоММ-4 http://handbookhmm.ru/pamyatka-dlya-heroes-iv.html
Памятка по НоММ-3 http://handbookhmm.ru/pamyatka-dlya-homm-iii.html
и HotA http://handbookhmm.ru/vyishla-obnovlennaya-pamyatka-dlya-homm-iii-hota.html