Sadly, many of a civ's features become pointless at low difficulty if your goal is purely speed, because as mentioned, you don't need Ikanda to win fast. They help when you're planning to do a Civil Service Impi Rush, but for a Chieftain Zulu game, it's not even necessary to tech Civil Service.
It is rather unfortunate, but that's the way it works kinda. I've been mulling over in my head the idea of challenges that start at the appropriate era to actually use the tech. For Zulu, maybe start in the classical era, so that you can immediately build Ikanda and you're only a few techs away from civil service. Maybe then it would actually better to wait. Even on Chieftain. I'm thinking the same way about a lot of civs, at least for Domination Gauntlets/Challenges below Immortal. I've had a similar frustration with the new G-Major for different reasons. Because it's an islands map, you need optics to attack. By the time you tech Optics, Construction, and Iron-working, you're way behind on tech unless you first focus on libraries/NC, which also delays those techs, so you're behind either way... whereas if it were a continents map, you could delay optics until after your kris rush. But, Indonesia works better on islands because it's a bit late to be settling cities *after* you clear your continent.
Basically I either end up attacking with XBows and Longswordsmen that I upgraded from Kris around t100+, or I end up suiciding into superior units with my kris on t80. So, for an Islands map, starting in the Classical Era would help. Otherwise you're basically not fighting until Medieval Era techs because of the scouting/exploration delay that teching Optics introduces. Less of an issue for someone like Denmark whose UU is a medieval unit... Ah well. Point is, not every civ is balanced for every map and time period, and at low levels, archers are enough.
