Flash

[Spoekes]

So if anything, I just want to know does it really take 3-5 now to properly - initially - generate and hold enmity? Or is this a widely-accepted but overkill method?

If by properly you mean to assure that you will not have to provoke a single enemy back from time to time the answer is definitly yes.
Like some ppl said, you can provoke+shieldlob every 40sec, but using provoke meant you lost the enmity race, which in my opinion is not good and I always feel like I failed

At level 50:
start fight with at least 3 flashes, factoring Circle of Scorn and Spirits Withing in between GCDs is just the safest way to start off the battle with a good lead in enmity.
On Speedruns keep flashing between combo rotations from time to time.

Below level 40:
Flash the hell out of everything, before shieldoath there is no other way to keep multiple targets on you, given that DPS are capable and not sleeping.

Disclaimer:
The above applies to groups of at least 3 enemies, of course.