If you Google " ira rmd" you end w/ this as one of the finds:
Retirement Plans FAQs regarding Required Minimum Distributions
Item 5 says you can take out of any one or more IRAs as long as you meet
the required total. It's different for 401Ks.
Can an account owner just take a RMD from one account instead of separately from each account?
An IRA owner must calculate the RMD separately for each IRA that he or she owns, but can withdraw the total amount from one or more of the IRAs. Similarly, a 403(b) contract owner must calculate the RMD separately for each 403(b) contract that he or she owns, but can take the total amount from one or more of the 403(b) contracts .
However, RMDs required from other types of retirement plans, such as 401(k) and 457(b) plans have to be taken separately from each of those plan accounts.