Harmony - Troop Symmetry

Let's return to the question of "machines":
It's not possible to create a branch of ballista -> rapid-fire ballista -> firearms because of the synergy between firearms and advanced ballistics – firearms would provide +150 fire damage and significantly increase the damage from three shots that ignore defense. If we do this, we'll get an overpowered unit and an imbalance in the machinery branches (everyone will only upgrade the ballista, except perhaps the Balsamizer; the other branches will be neglected).
That's why I decided to move firearms to the end of the catapult branch, but again, this presents the following choice: let's say we decide to go down the catapult branch and reach its second perk, "sulfur rain." Then, when choosing the third machinery perk, we'll have the following options:
1) start a new branch (tent)
2) start a new branch (ballista)
3) continue the catapult branch – take firearms
If the goal is to take a perk related to the ballista, the choice will be between the "ballista" and "fire arrows" perks, and in my opinion, it's more promising to take "ballista" because in both cases, we get ballista regeneration after battle and an increase in its damage, but the "ballista" perk additionally provides the ability to control the ballista independently.
Based on the above, we can conclude that no one will take firearms, and my goal is to make the choice equal (as with the choice between upgrading and alt-upgrading creatures).
P.S.: In this situation, the developers' decision to place firearms in the attack category doesn't seem so strange (but I'll still leave firearms in the machinery category).

Suggest your ideas, write down your options; for now, the machines will remain as they are