With big garrisons and recruitment stance of the armies, it actually make sense : you can not, as a small and unglorious faction, create more than a handful of armies. The guy who wrote this comment understood it backwards : the point IS that even if you have the money to maintain a thousand armies, you dont have the possibility to just roflstomp everyone in your path.
Winning the economy game will not give the player every tool to become the new world ruler in a matter of turns: now he will have to gradually "earn" it and as his empire grow he will ALWAYS have to manage his armies at peak efficiency and will never be able, whatever his treasury status is, to man every part of his territories with large armies.
We will have to choose where to send them and it will have a great impact on the strategy part of the campaign map.
Edit : now, even with a 3 or 6 armies limit, you can always choose to use 1 or 2 armies slot with a "recon-skirmish" kind of army. I guess except if you have huge income, you wont be able to 100% use all your armies slots with 20 veteran types of units anyway.
Then the comment about the AI being dumb at times isnt shocking. I just hope it isnt dumb all the time and sometimes will give a great challenge, even without giving them uber-buff with difficulties settings.