There are a lot of games in the 4x genre trying to solve the major issues. From longevity to stacks of doom they are all going about it in entirely the wrong way. The most common solutions for these issues involve abstractions and bandaids/limitations added to curtail player strategies. Instead of artificially limiting players, games need to provide systems where the desired behavior is a productive strategy for the player.
Since I've talked about longevity before I think I'll address the famous doomstack this time. A doomstack is when the player, or the AI, assembles its entire military into a single army. The goal is this is that combat algorithms in most 4x games give a higher kill to death ratio the more units there are between the totals of competing armies. 400 to 100 you lose 20 and 200 to 100 you lose 50. Paradox games allow for much more likely routs against smaller armies basically making armies disappear and need to be rebuilt instead of running away and then regenerating.
Many different studios and games attempted to resolve this issue. These were the most common solutions:
1UPT
Tile caps
Attrition %
Multi unit damage
These are merely treating the effects and not the cause. The solution to this problem and almost all the others in the 4x genre has always been to go after the causes. Contrary to popular belief, the cause of all the problems the 4x genre suffers is simplicity. There are trade offs of course but you have a choice of either adding complexity or accepting defeat as far as the historical problems the genre faces are concerned.
In this specific case there are several necessary systems and mechanics to be invoked. Attrition, logistics, and other specific systems must be employed the but the issue extends beyond that. Games must include reasons to split up stacks. Dominions3-4 deals with this issue somewhat in that you cannot leave provinces undefended without risking capture but its still a bit abstract and simplistic. In the ancient empires garrisons were necessary for defense from both internal and external assaults. Paradox games simulate this somewhat with the limitation that garrisons are non-interactive and are basically just a number but we can do much better.
In the majority of military history many victories were won by generals who cleverly attacked multiple fronts instead of grouping up and hunting down enemy doomstacks. Night attacks, sneak attacks, assassinations, feints and parries on the scale of armies. Paradox does the best job of dealing with the sort of rock and a hard place traps that often were important in warfare but like always they fall short of what can and should be done. Armies can charge in from all over the world as battles are fought over months or sometimes even years. Meanwhile defense is handled by the aforementioned automatic garrisons. Their recent EU4 switch to a fort system would be better if again they didn't implement it so abstractly.
Part of the failing of EU4 is how generic the combat units are. There is no training, no unique units, everything is drawn from a general manpower pool and Paradox games never implement the economics to go with their combat. Here the depth of Dominions3-4 is somewhat unique. Units are mostly unique to the provinces they were trained in. Racial units can often only be built in the original capital province of a race because they spawn based on special structures. Sadly you cannot build the special units of other races and there is generally only one province per nation with special training areas. Similarly in Paradox titles the nature of each province is rather unimportant and generic, perhaps barring trading bonused provinces and a couple really high tax ones.
So you need the time to get stuff done before armies can coalesce, interesting and significant provinces/cities to capture, logistics, attrition, and a system where huge numbers don't massively disadvantage weaker armies, whether that weakness is in quantity or quality of units.
Another alternative is war/espionage systems that offer other ways to fight a war. Rapid movement, chaff shredders, immunities, sabotage, and other ways to get things done and cause your opponent to have to shake up their tactics and strategies, but that's a topic for another post,
