A new tank with a question about combos.

[Shurrikhan]

Your best pull is almost always going to be Shield Lob straight into combos, with Flash only used where absolutely necessary and/or to maximize mitigation via blind. Keep in mind that your auto-attacks are also a factor, dealing 33.3 * weapon speed potency per hit. Opening with Rage of Halone barely hits for more and gives any beneficial actions dealt to you (buffs or healing) by your team a greater window by which to pull off you before you've hit the other enemies [i.e. "face-pull" time]. If the healer tends to instantly heal you, Lob, Flash, and go from there. If they open with Cleric and heal only as is necessary, you might well be able to go without using Flash at all, or at least use it only as mitigation. That said, it's better to use Flash sooner than later in the sense that the more mobs still up, the more good that Blind is doing.

The only time I use an uncombed Rage of Halone is when I'm standing at where an add will spawn and my team needs to kill that mob instantly, or on sprinting mass pulls where I don't want to waste mana for Flash on just one enemy nor use up so much TP as with a Shield Lob. (I have technically used Savage Blade uncomboed on a new add just to grab its attention in the part of a second before it picks its target for a special attack, after which it will be locked onto me for long enough for it to be killed even if someone else technically has enmity at death.)

Shield Lob = 120 x 4 >> 480 enmity [iirc]
Rage of Halone = 100/260 x 5 >> 500/1300 enmity
Savage Blade = 100/200 x 3.5 >> 350/700 enmity
Flash = 600 enmity AoE (but zero damage, unless you consider the mitigation done as healer offensive GCDs gained)