It looks like you’ve gotten good answers about your original RMD question.
Is DH satisfied with the performance of the three IRA annuities? Does he know what kind of annuities they are?
Many Bogleheads strongly dislike certain annuities like variable annuities and indexed annuities, while other types of annuities like multi year guaranteed annuities (MYGAs) are favored by many Bogleheads.
If he has purchased one or more unattractive annuities, he would be able to exchange those annuities back into a brokerage IRA with no current taxable income impact.
Please post back if you would like to further discuss his annuities.