Nah. That one is so unnecessarily unbalanced with having a Mafia team, that you are unlikely to win unless you lynch correctly Day 1. I prefer the SK version, which allows for actual strategy, since then it is a free-for-all. For all. And killing items could actually be balanced.
I'm unconvinced that the SK one would be balanced for the SKs.
What about a team that doesn't know each other?
Also, join anyway.
A team that doesn't know each other? That doesn't help, because that's... you know... town.
And the SK one is more balanced. It'll need some more power for the SKs, but it is much more balanced. Especially since their wincon is 1 of 2 or less remaining alive with no one with a kill alive.
Your Mafia tends to have a ridiculous amount of power, plus the ability to mafiakill. What this usually amounts to is an item pool that is nearly double or triple everyone else, the ability to work together and use multiple actions, and a constant kill. This could be balanced if the game weren't completely random. This means that you need people that are playing for themselves that must work against the randomness to win. It relies on more Day game, and less on the Night game, meaning even if they get super unlucky with items, they could still win, since the Town is unlikely to use killing items. And if they do get super lucky with items? Then they are STILL fighting by themselves. It doesn't matter if they pick of Grayswindir, since then they can't double-kill like the Mafia. Picking up a wand of death isn't an end-all for the town.
So, the SKs are more balanced, since randomness won't allow them to triple kill unless they get a Scroll of Genocide and read minds, they are focusing more on the day game anyhow, since they are unlikely to win with only night game, and they are on equal footing as the Town, as they may have to fight other SKs, just like them. The only downside is that they are less-powerful survivors. But, hey, that's what happens when you're an SK. You're on your own team.