You're thinking the wrong way, take you're time and read about what im going to tell you now.
I chose the Roman nation and honestly i wish i chose the brittish. Sure the romans may be nice but the 10% extra troop isnt that great i've noticed that you get 1 extra troop space per barrack upgrade and i thought it would be more, and not only that you will mostly use the legions and what i've noticed is that when you attack with that huge army the catapults hurts the army alot because of having so many troops together, and if you spread them out its gonna take even more time to kill the defensive buildings which will give the defender more time to spawn more troops to defend. Spreading them out also makes it easier for the towers to take them down. The catapults may not do much damage but it does enough for the other defensive objects to take care of army that will have half the health left. And upgrading the legions after classical age sucked, the extra health they got from the upgrade wasnt much and didnt help at all when i attacked a gun powder age nation, my troop actually got whiped fast.
The japanese are great offensive nation as well, hell everytime they attack me they whipe out my base extremly fast, that nation is actually great. I wouldve rather choosen them then the romans cause it would benefit alot in enlighment age from what i think.
The Germans are awesome too, they as well whipes my base right away cause of the damage they do and with the shorter rally time cool down makes it easier for them not to loose that much troops while raiding and trust me the germans are good!.
Now the reason why i would personally choose the Brittish is because they fit my playstyle, sure the archers are weak in the begining but you need to look at it from a different angle.
The brittish archers has a nice range to shoot down everything in their way which is actually awesome but they have a extremly hard time killing all the buildings, now as you all know you get more troop space in time by upgrading the barracks, so in time you will have enough troop space to build troops that can kill thoose buildings while the archers are "protecting" them from the defensive troops, not only that you also get troops donated from your alliances and u mostly get foot troops.
So yeah in time i think that the Germans and Brittish nations will be the ones that people will complain about later in game.
I personally regret choosing rome and building that amount army will frustrate you because of the amount of time it will take to build them all, rome is good tho but they are defenitly not the best.
I hope this helped all the new players, and dont do the same mistake i did, read the forums gain knowledge and dont forget that this game will keep evolving to space time.