The better way for me to proceed, since BOTH of the transfers were Trustee-to-Trustee, is to prepare corrected 1099-R forms per the process allowed in TurboTax. I have now done that and TurboTax no longer has a problem correctly computing the tax and there's no error indicated in the forms, so I should be able to e-file. Of course, I also can testify that I contacted the issuer of the incorrect 1099-R forms and they refused to correct them, arguing that the IRS will match up the receiving trustee's Form 5498. It's rather a CYA position on the part of the issuer of the 1099-R forms. They can escape this way because there's no penalty to them other than perhaps time spent with IRS if IRS decides to audit my return and them.
If my return gets audited and IRS requests my evidence, I will be relying on TurboTax Audit Protection, which I always purchase and they will have to deal with the IRS on my behalf. I was hoping to avoid all this but Financial Services LLC won't budge.