Raging strikes takes like...5 seconds to get. Since the person already said that their a DPS the chances of them having said skills is pretty high since quite a few classes take LNC as a sub job, if they were 100% new you'd be right.but in case they have one of 5 classes up those abilities will aid them greatly.
WAR's rotations don't get complicated until 50 and in dungeons you basically spam Over power until about 50% before going into single targeting...and WAR's rotation isn't really that complicated even at 50. The -10% damage isn't going to make that much of a difference on a boss nor would it prevent any good healer from DPSing, so really they can just spam Butcher's block combo and not care. T
Combo rotation 1 -> Combo rotation 2 -> Combo rotation 1.
Which @ 50, if they can't do said rotations, they should go back and level up another tank until they can, because all tanks from 50 on get more than one rotation. ;o
Before 50...
PLD is harder due to the sucktacular hate generation and doesn't get it's Tanking stance until 40 thus it's DEF is based on it's long cool downs and isn't up 100% of the time.. Have fun spamming flash and then going into playing wack-a-mob if you get any half way decent DPS. Can be done but hope you're good @ switching between mobs, checking individual hate on each mob, and dodging stuff all at once.
DRK has a lot of oGCD's and DA makes quite a few moves "use version A in X situation and use Version B in Y situation but only when I have W MP so I don't run out of MP for dark side."
War you just...spam over power. Hate is set. Only hard part is learning when to save stacks, use unchain, and iron beast which isn't really required with the job (at that point) and you an quite literately run through (not sprint) while spamming OP -> AFK for 10-15 seconds come back to a angry healer for having to spam cure on you due to being afk (if you want). Oh and Over power requires you position right, which is why I've suggested flash until they've gotten the hang of keeping all foes in front of them in a cone.
End Result: MRD/WAR allows you to set hate easily while introducing minor resource management in the form of TP. This allows you to focus on learning how to position correctly and how to time dodging attacks so you can move back into place without moving the mob but can be taken further and easily be a strong AoE job early on and in fact is among the few classes that gets it's AoE ability at a early level allowing for it to burn through mobs quite easily while keeping hate.
They are.