This is a fun topic. I see the tiers something like this:
Tier 1: Hicham El Guerrouj, Noureddine Morceli, '84 Sebastian Coe
Tier 2: Noah Ngeny, Asbel Kiprop (assuming juiced as he was), Jakob Ingebrigtsen
Tier 3: Taoufik Mahkloufi, Fermin Cacho
Tier 4: Matt Centrowitz, John Walker, Peter Rono
Hicham El Guerrouj is the best male 1500 runner, and arguably the best male distance runner, to ever live (and probably dope, but I am going to ignore that for the fun of it). But he is so much better than anyone else (7-1 over 1500/mile vs. Morceli, 21-1 vs. Ngeny) that I think the others are too smart to dare let him lead. I think that puts Morceli, '84 Coe, and Ngeny in the hunt. The only person I could see trying to lead aside from El G would be Jakob, knowing he's gonna get massacred that last 600 or so if he doesn't.
As much as I dislike Coevett I think we're disregarding Coe. He just didn't really lose big 1500 races that often, and 1:41.73 is no joke. I think there's a scenario where Hicham lets it dawdle (3:32 or slower race) and Coe wins it all. If he doesn't, I think Ngeny just bides his time between El G, Jakob, and others and wins like he did in Sydney. Remember, by almost all metrics, 2000 was El G's prime, and he got beat. He was in better overall shape that year than in 2004.
Final answer: The field starts bunched up as El G hopes and prays that someone will start pouring in some pace. They do not. Asbel is loping around in last place. They go through 400 in 62.1 and with that pace continuing, through 600 at 1:32.9, El G takes over at 600 and rachets it down -- they go through 800 in 2:00.9. He continues to lead and the pack starts to thin. Jakob leads an odd chase pack about 5-10m off the lead and so does all of his own leading despite being about a second back. Asbel sprints up to El G's shoulder at 1000, which they pass in 2:27.8, but then the sudden pace injection gets to him and he falls back into the pack. El G goes through 1200 in 2:54.7 (53.8 3rd 400), with Morceli just behind him. Ngeny, then '84 Coe. Makhloufi and Cacho makes a move to latch on to them but they gave a bit too much room.
El G hangs onto the inside and distances from Morceli over the next 200, but Ngeny swings around him and '84 Coe follows him around the bend. They pass Morceli. El G pours it all into the final 300 and runs a 39.2 final 300 for a 3:33.9 and blazing final 1000, but Coe inches by him just before the line in 3:33.7. Ngeny lets up before the line when he know she can't catch either of them and is almost caught by Morceli. Asbel yo-yos his way to 7th, not able to catch Jakob in the straight, who gets kicked past by Makh daddy.
1. '84 Sebastian Coe, 3:33.7
2. Hicham El Guerrouj, 3:33.9
3. Noah Ngeny, 3:34.4
4. Noureddine Morceli, 3:34.5
5. Taofik Makhloufi, 3:34.9
6. Jakob Ingebrigtsen, 3:35.0
7. Asbel Kiprop, 3:35.3
8. Fermin Cacho, 3:36.1