Personally, I've found that level syncing can be the biggest factor in how easy or hard tanking is, especially with people playing on classes rather than jobs. I was doing halatali on my L32 Monk before, and the tank was a L22 gladiator or so. Needless to say, I had to literally play at half-speed in order to not take enmity, as my standard damage combo seemed to generate more enmity than the gladiators enmity combo (at that level). If the enemy was near death, then I would sometimes just take it in the last few rounds and rely on Fist of Earth (-10% dmg received) and Featherfoot/Second Wind to cover me. I would also have to frequently cycle targets to ensure I was doing damage all the time, but not taking enmity (as in, dealing damage on primary target until 5% off enmity threshold, then go to secondary target until 5% off, then third target etc.)

The tank in question was reasonably well geared as well, full L20 hq crafted gear, and they were using the right skills. But they still had nearly 20% less hp than me synced (I had around 610hp, they had 450 or so) and the above issues. Level syncing and job bonuses are just very powerful in low level duty roulette. As a comparison, my main is L50 Warrior, been playing it since launch and pretty much fully kitted out (just finishing off primals for weapon then 1 allagan acc.). I can be very lazy and not pay attention in low level roulette because there's just no competition for enmity 99% of the time.