Mobius is fine. Maybe if you really want, it can be down to 2, but nobody uses more than 2 anyway even if we include the sidedeck. Jinzo is down to 1 because after it's summoned, it's relatively more difficult to take down than Mobius. Traps can't be used at all, so you're down to monster effects and spells to get it. On the other hand, though Mobius is destruction and not negation, and it can target spells on top of traps, it's easier to destroy. You can set a widespread or sakuretsu after Mobius is summoned already and destroy it that way. Also, like all the Monarchs, Tsukuyomi can destroy Mobius by herself, while Tsukuyomi will be needing a bit of help to get Jinzo. Jinzo's effect is reusable through recursion, but Mobius is only a beatstick if it gets revived, so that's also a plus for Jinzo.
For all the reasons above, Jinzo is at 1 while Mobius isn't restricted.
Plus, personally I think that we shouldn't talk of restricting monsters so lightly unless it has the power to turn the tide for the entire metagame, generates card/field advantages easily, or if that one monster can completely shutdown a decktype.
Mobius can't do any of those. It's in many decks but it's not guarantee loss if you don't have it either, unlike BLS back then. It doesn't generate card/field advantage too easily, because it requires a tribute. Also it's only a 2 for 3 if both s/t can't be chained, and successfully destroys a monster on top of it (most of the time it's 2 for 2 as one of the s/t will chain to Mobius so it won't go wasted.) Mobius obviously doesn't shut down an entire decktype, seeing how last format a burn deck made it to Top 8 against all those Mobius out there.
Multiple Jinzos on the other hand have the power to turn the entire metagame by changing a lot of decks to a "3 staple traps only" type of thing (or something to the line of extremely low trap count.) Multiple Jinzo spells CHAOS *pun.*
