If you're only having a tank as a side class and don't intend to play tanks extensively: Go for the one that is aesthetically pleasing to you. In this case, WAR since you like to run around with a big axe. Part of the game is after all enjoying how your character looks.

If you want to become a full time tank/exceptional tank player: Go both.

Just know that whichever choice you make, you shouldn't be excluded from any content by the choice of your class.