Abstraction: Managing a Large Economy and Large Armies
In my opinion the biggest and most important feature in Ashes of the Singularity is not the number of units that will be in play; it is the command and control system that players will use to manage such large armies.
The devs have publicly announced that they will use a "battlegroup" type system to group units together into larger entities in order to facilitate controlling large numbers of units. This is a huge step forward for RTS games, and its significance cannot be overstated.
However, in some other areas I am left with the distinct impression that Ashes is still locked into a traditional RTS line of thinking when instead the principle that the player is controlling an entire WAR, and not a single battle, should control.
For example, the hotkey system used to produce units. Although a very functional hotkey system, comparable to several other RTS games like Grey Goo, in my opinion Ashes of the Singularity needs something more. In Ashes it is possible to quickly assign unit construction orders using the keyboard, such as QEQ to build a Hyperion. However, in my opinion this approach is fundamentally misguided.
Automation
Instead, Ashes should be designed with the assumption that the player's UI should manage the low-level actions. This includes unit AI like moving and shooting primitive commands, but should also include basic economic actions such as issuing individual unit construction orders.
Under the current Ashes system the player is still manually constructing individual units. Which, even if units are created in squads of three or so, is still a lot of keypresses to build units manually.
What Ashes needs is automation to save the player from manually executing such basic commands a large number of times. This will free the player's attention to focus on the actual war, and make interesting strategic decisions rather than spend the entire game building units and ensuring resources are being efficiently managed in the small scale.
A simple and familiar way to do this would be a simple "infinite repeat" toggle. That would be functional, but in my opinion is selling the potential of Ashes short.
Abstraction
The best way to implement this type of automation is by formally declaring that players should be working with higher level logical entities than individual units and individual structures.
What do I mean by this? In almost every RTS game created to date the player controls individual units, mainly using selection and issuing primitive orders to groups at a time. Control groups make this "group primitive" order system more convenient, but introduces a new requirement that the player add and remove units from those control groups to maintain their usefulness.
Ashes should allow players to create groups which have significance for controlling their behavior, not just making it easier for players to recall group selections. For example, a group of factories would work together to fulfill a large production order, splitting the unit production between member factories.
As a more useful example, a base might be composed of several building sub-groups. This would allow the player to build a complex base somewhere else on the map easily. And it would also allow an existing base to receive more complex orders. Such as instructing the base to increase its production capacity without having to hunt for engineers inside the base. A base might maintain a specified number of engineers and replace them if they are lost, as well as functional modules for production, defenses, logistics, base garrison units, air force interceptor or bomber squadrons, repair units, and anything else the base might need.
Player Focus on the War, not Small Scale
Long story short, every time the player has to manually build a unit, that player is performing a chore that a computer could do much more effectively. A hotkey system makes this chore faster, but it remains a chore.
Liberating the player from these chores allows the player to focus on the war, on the strategic scale. I want to be able to specify what I want done, and have the UI implement that decision, like staff officers for a general.
The player should give orders more along the lines of "that army should go there" or "this base should supply reinforcements to that army" or "I want an airbase built here." This is a very different approach from the classical RTS system of issuing orders like "move" and "attack."
Conclusion
Ashes intends to have more units than any RTS ever. Without equally advanced command and control systems to allow players to make effective use of so many units, players are going to exercise very little control over their units because they won't have much choice. It's just not feasible to carefully manage ten thousand units. But a single blob of ten thousand? That much, a human can do.
However by using AI to augment the player's management ability, players will be less burdened by tasks like raiding an outpost, performing an air strike, or building a new base. As a result, players' ability to be active and spread out will be greatly enhanced, which is vitally important to avoid players just giving up and making mindless all-out attacks with the largest blobs they can muster.