I want to give a suggestion about troops.
How about create Champions ( Gauls and Teutons) and Centurions (Romans) to act like a minimal hero boost to the troops.
They will work as this:
Will be trained from an existing unit already researched ( not adventure reward troop), and will become a better version that unit. Limited a one at time ( like a hero)
This unit will have a doubled stats of a unit they came from ( like a clubswinger with 80 atk and 40/10 defense) and will give a small boost to troops of same type.
These mechanics are from the old hero version of travian, so they already have a code for this.
This unit will have hidden stats progression, so you cannot chose a benefit for lvl up , but they will grow stats and bonus at 1/3 speed of hero experience.
This unit will not have any equips or inventory or avatar, they will just a unit on your army.
This unit will keep the crop consumption of the base unit.
This unit will be cap to a max stat of base*5, (max bonus for units of same type is equal a tier 2 hero weapon) so not so expressive or unbalanced.
You can use a barracks/Stable to see and manage this unit, depending if is infantry or cavalry
the goal is to create a way to get strenght to a second unit, on defense or offence, because a hero weapon can benefit only one troop type.
So you can have a hero with a druid staff, and a phalanx champion giving (+1 defense/lvl )to each phalanx, for exemple,
or have a Teuton hero with an axe, and a champion teuton Knight giving (+3 atk/lvl) to eack TK
or even you can add up to +66% the bonus added to an unit type, using a hero weapon who benefit that unit ( ok, this could be so much..)
Example, having a praetorian Centurion, plus a weapon on hero what gives bonus to each praetorian following that hero..