>Maul shouldn't be put in situations where he has to emote though
I disagree, that's just incredibly limiting in regards to storytelling.
>there HAS to be a WHOLE PLANET of those cool things.
In regards to Boba (and believe me, I am no Bobafag), there was ALWAYS going to be a planet of Mandalorians. He was described, even in the earliest stages of production, as being a Bounty Hunter who wears Mandalorian Supercommando armor.
His armor was never supposed to be 1-of-a-kind. Lucas got around this by explaining that Boba isn't even a Mandalorian, so technically Boba is still unique, the Mandalorians were always supposed to be a separate faction unrelated to him. And yeah, I know, the Clones.
>There has to be loads of other maul looking guys running around, and he needs a brother whos bigger and stronger than him and also has a lightsaber!!!11.
This was all explained in the show though. It's not that they pulled it out of their ass.
The arc was cleverly constructed so that it could be used as a platform for Ventress to go off on her own. Then Dooku needs a replacement, and they used the introduction of a new villain character as the launchpad to work Maul into the story. Then making Maul come from a tribal family is a no-brainer, just look at the guy.
It was all very fluid and thought-out well. And Maul's relationship with his brother is frankly one of my favorite parts about the character now. It's incredibly subtle throughout the show, and yet it's undeniable that Maul actually did care about Savage. Especially when you see Maul in Rebels.
Also the fight against Sheev is one of the best high-stakes fights in the entire franchise. The visuals were top notch, as was Sheev's cackling, the TPM pottery, and we had no idea if Maul was going to survive the Sheevening.
My only regret is that Son of Dathomir never got animated. Maul confronting Greivous and Dooku personally would have been fucking amazing to see on screen.