Is it a red flag if a program’s residents don’t stay at the program for fellowship.

There are two programs I’m highly considering. Program A is a top 10 IM program. However, looking at their match list in PCCM for the past 4 years, none of the residents have stayed at the program for fellowship. Is that a red flag? Although, the residents match very well in PCCM at other prestigious or even more prestigious institutions like MGH. Program B however is ranked within top 10-20. The residents who go on to PCCM match at the home program, ie this program’s PCCM fellowship consists mostly of people who did residency at the program. How do I factor this in my decision?

Summary; Program A rarely matches its own residents for PCCM, but this residency provides stronger clinical training, and is more prestigious with a stronger reputation.

Program B mostly takes its own residents for PCCM fellowship, this residency provides strong clinical training, among T20, but doesn’t have the same level of prestige and reputation as program 1. Both programs are in the same city.

Any advice or input would be greatly appreciated.