Thanks, I main PLD/DRK so I don't get to see what other tanks do too often, was very surprised when I started running end-game dungeons on my DRG instead. I tend to only use kill order marking in low-level roulettes if I see multiple jobless people. Otherwise as you say I assume the dps will engage the more dangerous mob first (or AoE if I've done that style pull), but I also try to "tag" that mob first with the range pull as a helpful hint to them before spread the hate around.
The exact trend I've been seeing was
unmend turtle, unleash hitting the two crawlers, hate combo on one crawler, delirium combo same crawler, hate combo other crawler, DASE first crawler. -- Three different DRKs Seems like some site must be teaching that as a rotation/strategy, but I can't understand why,. All while other dps and I are playing pass the turtle before we notice what the tank is doing and switch to the drawler that the tank apparently wants dead.