Ok, I only play SM, so that's what I'm going to talk about.
The Force Commander's terminator upgrade is horrible and nobody ever buys it. It's pretty much the most expensive hero upgrade in the game but turning your Offensive hero into a ranged unit that lacks any sort of retreat is a really bad thing. Really really bad. There needs to be some improvement. Perhaps give him a Thunder Hammer and Stormshield option, perhaps a retreat, perhaps a teleport? Something needs to be done to make it an actual viable upgrade to use.
The Force Commander's global ability For the Emperor is also quite bad. Nobody ever uses zeal for it, since it turns your targeted unit into a statue that can be killed pretty easily. I was thinking perhaps it could be changed into an ability that gives your unit increased knockback for ranged attacks, but that might be overpowered in conjunction with ATSKNF. So, not entirely sure what it should be changed to, but it's certainly useless in its current form.
Terminators and Assault Terminators right now aren't worth their cost. 900 requisition and 700 zeal are a huge price to pay for a unit that's mostly lackluster. Only the Terminator w/ Cyclone missile launcher is anywhere near useful enough to that price right now. And that's only because the Cyclone launcher is really overpowered compared to the other two weapon options. For costing as much as they do, Terminators and Assault Terminators are destroyed by Seer Councils and upgraded Nobs. Assault Terminators in particular receive no defensive bonus for holding stormshields, only the 40% melee resistance that all melee troops are endowed with. They look to have a lot of health, but this is countered by them being size Large, which means that everything on the field is able to hit them, such as AV weaponry. Missiles that will miss nobs and other infantry 95% of the time will hit Terminators 100% of the time. So their health goes down much quicker then one would expect. But they also lack a retreat option. This seems very strange, since other heavy infantry like the Seer Council and Nobs have retreat. It's thus very easy to preserve those high cost units, except in extreme circumstances. With Terminators, you're limited to a 30 foot teleport with a 60 second cooldown, after which your very very slow Terminators will still get caught up to. This isn't good for such an expensive unit and most SM players will simply choose to build more tac squads.
The failings of the Terminators and the recent nerf to OB are bad, but the actual buildable T3 unit for SM, the Predator, is also generally shunned. This means that SMs usually never try to tech for T3. Only the Dark Age of Technology upgrade is worthwhile, and that's rare to use since Dreadnoughts are rarely built. The problem with the Predator is that it's much too fragile in battle for the price. This fragility combined with the spotty vehicle pathfinding means SM players will prefer to build more tac squads.
Nobody uses the flamer upgrade for tac squads since it's only useful in T1 against swarms or generators. Plasma guns or missile launchers are infinitely more valuable and always stay effective, so the flamer might as well not exist. Perhaps you could leave the option to upgrade to either the plasma gun or the missile launcher after equipping the flamer, with the limitation that the second upgrade is the final one? It would encourage people to actually equip and utilize the flamer, while not punishing them in the later game with an obsolete tac squad whose pop cap you can only get rid of by sacrificing to the enemy.
The overall melee vs ranged dynamic is okay, except for the retreat damage. Ranged does 20% damage to retreating forces, while melee does 130% damage to retreating forces. This is a very heavy disadvantage for ranged forces in general, and SM units in particular since the Eldar at least have access to fleet of foot which avoids the retreat dmg bonus. Right now, melee does very heavy damage compared to ranged in the normal battlefield, there is no reason to have such a large and punishing disparity for the retreat mechanic. Or if the bonus should stay, attacking melee units should not be able to block the retreating squads. Retreat, I feel, should be a way of saving your unit while sacrificing the field to the opponent, and right now I don't feel that's true with the melee damage bonus. A lot of retreating units are not preserved, but simply killed more quickly when pursued and hit by melee units. Ceding the field and also losing the unit in the process. That's too punishing and defeats the purpose of having a retreat mechanic in the first place, in my eyes. Perhaps a flat 30 or 40% damage to retreating units for both ranged and melee would be alright? Not sure about the exact percentage of damage, but melee is way too good right now.