
I play WAR/NIN and tank in my static. I found WAR/MNK to be a great tanking job up to the mid-40s, which is when I switched to WAR/NIN. THF is a WAR's best friend, as a THF can glue on the hate a WAR/NIN needs.
At early levels, I out-tanked plenty of newbie PLDs. I even out-tanked a PLD in Crawler's Nest. That doesn't mean that WAR > PLD. Even I will concede that PLDs can be better tanks. WARs are just different.
As others have said, if you want to be a tank all the way, be a PLD. If you want the flexibility to tank and/or deal damage, go with WAR.