I think that answer is wrong. You need to enter both 1099R forms unless they are for the same distribution. Didn't you say you took a distribution from each custodian? How much is the RMD you were suppose to take on the 12/31/23 account balance? So you took some of it from the TDA account and the rest from Schwab?
Don't worry about the RMD showing double. The IRS doesn't get that info or know what your RMD should be. You have to enter each 1099R. When it asks about the RMD it is only asking for that one 1099R. You need to enter the amount in box 1 on that single 1099R for the RMD, not the total RMD for all. Even if they would add up to more or less.
So for your example...was $3,000 the total RMD you needed to take?
So for the TDA 1099R you enter the $1,000 amount in box 1 and say yes it was the full RMD and enter just that $1,000 amount as the RMD amount. Then on the Schwab 1099R $2,000 you say yes it the full RMD and only enter the the $2,000 as the RMD amount. You don't enter the full 3,000 for both 1099Rs.
