Well maybe not unlimit the unit limit.. but the game has to develop in the feature and some empires has to grow.. bye unlimit i meant, if you conquer another player, you'll gain his stronghold. then some of his population, which should increase your ability to have more units, that sounds reasonable, and secondly.. i dont think players will send several thousand of soldiers to each others... they will probobly be spread out alot..
Late game some players will be superior power, and with only 1.000 men in total? that sounds very small to me.. Alternative would be to have a unit limit in a battle, 2.000 max, whereas it is possible to have now.. but your still able to build more units, around your empire..
Limited population is just a typical thing about all rts games.. yes.. its because of avoid lags and bad performance.. but this game is supose to be epic!
I would really dislike the fact that you have to start sacrifice your peasents just to gain more pop for soldiers, in late game..