Monthly vesting without a year one cliff is not really done, AFAIK. I also don't think that there is a lot of wiggle room for negotiated severance terms. But sign on bonuses and 200k base pay could certainly be on the table.
Facebook definitely doesn't have a cliff in 2020.
Some grants (small) once a year Bigger - quarterly Large - monthly
It's very similar to a sign-on bonus you can claw back in the first year or two.