From my point of view the game is too slow at the beginning. I thought about adjusting costs of military units so the civilization would be able to build each of them in 5 turns tops.
For Ancient Era it would all have to be cut -80%. For other eras the cut would need to be smaller as the city production is increasing. For Modern Era cutting would not be needed at all.
What would be the result of that - more wars, small wars, especially in the beginning. Now the units are to expensive to risk a war with 1 unit, and to get a reasonable amount of them I would need to wait 1000-2000 years (because I cannot focus on building units all the time).
Second problem that it solves is that usually I get Archery and Bronze Working even before I thing about building second unit so a "little moster" called Warrior is usually a single freak in my army (unless I find a ruin and it's gets free upgrade to Spearmen
)