I understand your point, but our developers have their own vision of the game, and it should come as no surprise that the game development process is mostly based on their vision, and their plans. Of course, multiple factors are taken into consideration: analytics, stats, player feedback and suggestions, marketing research, and many other things. However, neither of the factors can be prevalent. We understand that some players would like others to have smaller armies. However, it's not the direction we'd like our game to evolve in.
We strive for the massive battles, not small local fights. We give players an opportunity to unite against the stronger enemy. Only up to 3 players can attack at the same time. And 160 can defend (if we're talking about the Capital or a Pantheon). 3 against 160! Even if those 3 have huge armies, they're still limited with how much they can send at a time. And the Defenders have no limits. All your power can be combined against the upcoming attack. And it's up to the Coalition leadership to motivate their Coalition mates to send their Defense to protect their Coalition's strategic points.
A single player cannot defeat the joint Defense, even if he has a huge army. This game is not about single warriors, it's about coalitions, unions, allies, sacrifice of your own Units for the common good, etc. It's hard, challenging, sometimes it may seem almost impossible. It's easier to say that the things are not fair, that some players have bigger armies while you have nothing to put against them. But there's also another way, which is much harder, but which can bring you to the glory - build, fight, unite, use all your potential, motivate others, and show your enemies no mercy!