You can always make the decision to play a different army; it's the uniqueness of the armies that is one of the great strengths of 9th Age imoNo need to only find arguments in a "black or white" style. Nobody asked for all playstyles equally good for all armies. But it is also not good to have only one playstyle available per army. I want to make my own decisions about how I play my armies. There should be strength and weaknesses for armies, not forced and forbidden playstyles.But then what is the difference between the armies? One of the complaints leveled against KoW is that all of the armies feel the same. If you have similar play styles among all of the armies, they lose their identity.I disagree on playstyles. Do not be afraid to broaden the metagame. WotDG with some basic short, medium and long range shooting? Why not? Suicide Elves? Why not? TVI EoS? Why not?
And what if I don't want to change my army to play another style? If I want to try different concepts with the same army?
Because that is what I do. I own 8 different armies and still I change the playstyle of each one after a couple of games because I want to.
Even unique armies don't have to be played with the same style every single game. That should be left to the players how they play their army. Give them weaknesses, make some aproaches harder to use, even leave something completely out of an army list on very rare occasions, but don't set the playstyle of an army in stone. It will get boring pretty soon.