Victoria vs Gandhi
First of all I have no idea how Victoria got this far. Good all around but nothing that jumps in your face and especially nothing that helps you early. If you get an early advantage it will help throughout the game and this can decide the game. A few fast settlers are not going to do, what philosophical can do for you, and spiritual is simply amazing. Both of Gandhis traits have to be worked a little bit, but the payoff can be huge.
His UU lasts forever and is a constant advantage (just like spiritual). Redcoats are a good unit but nothing amazing and they're lifetime is limited.
Now the english UB is a lot better than the Masoleum but again I can't weigh them enough to push the result in favor of Victoria.
Mansa Musa vs Shaka
Both good leaders and both come out of completely different corners. Mansa has again the always powerful spiritual trait and with financial you will always get what you pay for (pun intended).
Shaka has aggressive, which is a solid advantage over non agg. civs for a long time. Expansive with the boost is a very nice trait, but again the bonus to workers might not be that big. But on top he gets 2 health and 2 cheap buildings.
The UUs are both not that great. Skirmishers make you a tough nut to crack early on, but that's hardly gamebraking. Of course sometimes you can rush someone with Skirmishers, rarely though. The Impi has some uses. He gives you early security but can also be an annoyance for the opponent. Impis are better in my opinion if only for the fact, that they counter some of the best UUs in the game (Immortals, War Chariots) and can catch Keshiks.
I don't like Musas UB too much but at least it has nice a synergy with financial and his general playing style. Shakas UB lets you war more early on and also fits him nicely. But I think it's more powerful because you get it cheap with aggressive and later on, you can get an easy -70% maintenance. Something which other leaders simply can't.
Overall those two are very close to a tie in my book, but I have to give the nod to Shaka.
1. Gandhi
2. Victoria
3. Shaka
4. Mansa Musa