https://www.ftb.ca.gov/forms/2020/2020-1032-publication.pdf

and https://www.ftb.ca.gov/file/personal/filing-situations/military.html

Is this a permanent or temporary assignment outside of California?

Its a temporary assignment outside of California.

Military only files state where they joined up, unless they request a change. Their W2 should have withholdings from only one state, and that would be state you file.

Is the MO W-2 from a nonmilitary job?

You need to research the MO rules to see if it MO income. Very likely you file CA as resident (away from home on temporary assignment) and MO as Non Resident. CA probably gives credit for MO taxes. 

Ain't doin' taxes fun? Sorta like a jig saw puzzle where you don't know what the picture is and you are sure you lost a few pieces under the sofa.