(Looking past the fact that stationary Artillery and strategic bombers are OP.) The current unit meta is arguably focused around "tanks" - Athena and Mauler. Even if the Athena is nerfed. I think the units are still quite too similar to one another. So Im suggesting a broad balance change on all units to allow a greater focus on diverse usage of units, as opposed to blobs of units that nobody really uses the advantage of one over the other.

I think the recent nerf to the Artemis just added to this effect that the units are too similar. So here's some rough ideas on simple changes, if someone can apply values to the changes that would be cool:

PHC Changes:

Brute - Large HP Buff, Minor Bamage Buff  (encourage the use of T1)
Archer - Large Damage Buff, Minor HP Buff  (encourage the use of T1)

Artemis - Range + Damage Buff, Heavy Speed Nerf when firing long range weapons
Nemesis - Range + Damage Buff, RoF Nerf
Athena - Damage Nerf
Apollo- Large AA Damage Buff
Zeus- AOE Damage Buff. Possible HP Buff.

Cronus - Damage Buff, Heavy Speed Nerf when firing long range weapons
Promethius- Damage Buff, RoF Reduction on main gun. Speed when firing main gun.

Hades- HP Buff.(so can actually reach enemy defenses) Put behind a tech wall.
Furies- AA Damage Buff.

Air Marauder - Damage Buff. Remove the requirement of the Dreadlaunch.
Strat Bomber- HP Nerf. Tech Wall (since Dreadlaunch requirement removed on factory)

U get the idea. Make the unit better at what it is supposed to be good at. Dont make everything one large bland soup. The arty + bombers will then be able to pierce defenses, while the tech wall will prevent early bomber rushing from wrecking players from the start.

What this will hopefully discourage is the spamming of any single unit, since if the enemy spams "tanks" u take Nemesis. If they spam Arty u take tanks. If someone turtles u take mobile arty (since then it could actually do something).

If someone spams Dreads (somehow) u can then take Nemesis, currently a hyperion is almost unkillable, atleast with better Nemesis and Promethius there will be a counter for it.

If the enemy spams bombers u go furies OR apollo. (currently its only >T1 Defenses or mass furies). Pure air spam, u take Apollos. (currently its only >T2 Defenses)

Substrate Changes:(highly experimental)

Reaper: Large Damage Buff, Minor HP Buff  (encourage the use of T1)
Martyr:  Large HP Buff, Minor Bamage Buff  (encourage the use of T1)
Capacitor: HP Buff
Sky Cleanser: HP Buff (encourage the use of T1)

Avenger: RoF Increase. Damage Nerf. (specifically to counter T1)
Destructor: Range + Damage Buff, Speed Nerf when firing long range weapons
Drone Hive: Minor Damage Buff on Drones, Drones launch from a greater range.
Mauler: Minor HP Buff
Caregiver: Log Reduction. Minor Shield Regen Buff.
Eradicator: HP Buff, Speed Nerf on firing main gun.
Masochist:Tough one, not sure.

Dominator: Minor anti ground damage buff. Tech wall.
Punisher: Tech wall.

Air Rampage: Damage Buff. Remove the requirement of the Dreadlaunch.
Harby: Minor Damage + HP Buff. Tech Wall (since Dreadlaunch requirement removed on aviary)

Ravager: Speed Nerf when firing main gun.
Overmind: Minor Speed Nerf. Increase drone build rate of accompanying Drone Hives.
Retributor: Minor Forward Speed Buff.

What we can see here is SS suffers from lack of anti armour, except for their air units. So possibly as an alternative is to give reapers armour piercing weapons. Its weird but it would make a big difference between SS and PHC. Reapers would get a nerf to building damage (to counter for the AP shots). If PHC goes mass armour, SS goes reapers, or Punishers or Rampagers. If SS goes mass Reapers, PHC goes Zeus or Artemis. If PHC goes Artemis, SS goes Maulers (since Artemis should kill Drone Hives), if Zeus then Drones. And so on and so forth, as opposed to, "go Athenas to win".

SS would then specialise in Drones, Air, and Mass units (a la reapers). While PHC would specialise in heavy and long range units.