Domination on Huge?! And on timely, natural manner too, solid 10 turns before science and cultural victories were possible. Of course it's on Epic speed. I think Epic speed is more suited for Huge maps due the bigger spaces that have to be covered and more cities that need to be considered. Difficulty Immortal.
Here's what enabled it;
-
Warlike religion, this is a bit of a weird one. There's 1 belief of each type for warmongering. I've seen a some players here really keen on picking them all up, and being disappointed if they are unable. I think this is something that should only be consistently done by religious warmongers like Montezuma or Genghis (Ger). Or by very religious civs that want to play as warmongers like Byzantium. Warmongering especially has little need to founding themselves because you always got the option to capture another Holy City. Nevertheless I did get all of the war beliefs in this game, sans Orders. Every belief I picked ties to some future point in this list.
-
Combat bonuses, hands down, most important one here. With enough combat bonuses it was possibly to overwhelm even Askia, who had a tech advantage at the time that I invaded his continent (my Tanks were beating his Modern Armor), not to mention later 3 shotting the cities of those still in Atomic era. A fair amount of that came from Autocracy's Lightning Warfare and Martial Spirit, as well as extra XP from elite forces, I was the only one to pick Autocracy and that helped. Strategic Monopolies were also very impactful (Oil and Coal monopolies did seem to work), with Zealotry and the Third Alternative tenet as well as well planned conquests it was possible to get them in a Huge map. Other bonuses from Crusader Spirit, Authority, Global Wargames, Treasure Fleet, and Imperialism (Ironsides) and Statue of Zeus. Of course I had to content with -10% or, even -20% at times

modifier but did not notice any major warmonger penalties.
-
Late game units. There are absolutely the tools to make rapid conquests in the late game. I might go into more depth about late game war in a relevant thread, but the MVPs were Tanks and Modern Armor, especially Drill-Blitz promoted to take cities with, the Bomber and Fighter line, Cruisers and Battleships, Destroyers and Missile Cruisers, Carriers (for this map) and Helicopters (Mongolian UA). The Infantry and Mech Infantry were alright, they couldn't keep up with Tanks and Light tanks but did reasonable damage to cities and could be airlifted to a newly conquered one. Special Forces and XCOM were decent, especially for citadel pillaging. Artillery was okay too, a bit slow, some damage to cities though. Foot ranged units seems more defensively inclined, they can't really keep up with tanks. GDRs is when conquests became really rapid though, if CV has the Internet tech, and Diplo has Globalization, well, Domination Victory has.. Robotics I guess.
Of course that's a lot of Strategic resources used, someone going for Domination should spend the mid game securing them.
-Autocracy's
Air Superiority Tenet; Well, maybe a bit map specific, this was a lifesaver. The free Airport makes rapid conquests possible in those continent type maps. Absolutely one of my favourite tenets to get, it really changes the way the game is played.
-
Infinite 
towards the end of the game, to feed Upgrades, Public Works, unit and building purchases and everything really, even mass-buying Guided Missiles. While I had this before with Commerce Raiders tenet, this time I was able to skip it, not even sure why. I guess the gold on city capture from Crusader Spirit and Imperialism was enough. Good gold income (mainly from trading Strategics) helped in earlier eras too, in mass buying Foreign Legions in order to kickstart some conquests.
-
Infinite 
and Zealotry. While I did miss Orders, it was possible to acquire them in a timely manner, by conquering the continent of the one that had them in Industrial. Along with faith from God of War and Hero Warship on unit kill and city conquest respectively. Don't think this was totally necessary, my unit production was very good either way especially with Centaurus Corp, but I was able to totally skip it towards the end in favor of Processes and Public Works and late game buildings. Mass Faith buying also gave

and

from Veneration.
About

;
William and Askia were giving me severe Poverty Boredom and Illiteracy pressure even before mass conquests. I had to build a fair amount of Public Works, even starting in the Industrial, average of 4 per city I think? This wasn't a big problem though. Other ways I've used to deal with it was to use the large amounts of

and

for buildings, use Processes when able, Landmarks, Hydroelectric and Wind Plant yields helped a lot with

Needs too. Autocracy has a -fair- amount of Happiness too, between Prora, Police Stations as well as Courthouses, not nearly as much as the other trees, I think, not a bad thing. Had to do some select Annexations and Razing.
Authority's Policies scale pretty well into the late game so had a fair amount of

to get some policies past the 4 T2 and 1 T3 tenets I considered essential.
Some good ones for

were;
Rationalism opener and Enlightenment. 2 Policies
Industry's Division of Labor and Entrepreneurship. 3 Policies
Progress' Equality, most impactful one. 3 Policies
Statecraft and Tradition openers.
Of course I had Mongolia's

from tribute yields, but even without that, someone on the way to Domination should have great Culture gain from Prora, unit kills and city conquests.
In general,

wasn't a real threat either way. By the time I set out to invade the runaway Songhai, to 30 turns later when Domination Victory was achieved, I already had everything I needed to close out the game, the only annoyance being the combat penalty.
Since I played a decent amount (by my standards) of games in the latest patches, I'll bring up some observations/wackiness I've noticed, later, when I have time again. Does ilteroi read these threads? I think they mostly concern him