Certainly I have cautioned that proponents of same sex marriage have put their own feelings ahead of strategic thinking. But in this case I think Frank is wrong and Nadler correct. The popular mood on this has shifted considerably over time in favor of recognition of same sex marriage, and will continue to do so. (Recall that in 2007, only Dennis Kucinich supported same sex marriage and the other D candidates supported civil unions.) Those opposed are unutterably and totally opposed to any "pro-gay" legislation -- as are their constituents. This cautions against an incrimentalist approach in that it doesn't buy you anything.
The only strategy on incrimentlism here is with the wussy D leadership. In which case the stronger bill as a rallying point should help, rather than hurt, passage of the other bills. Ds will need to do something concrete for the same-sex constituency. If they cannot swing RFMA, they should certainly be able to get Don't Ask repealed.
The presence of the RFMA also puts pressure on Obama, who has stated theoretical support for repeal of DOMA, to come out in favor of the actual Bill. I imagine that we will see considerable pressure from the gay community for Obama to include RFMA and the other bills in the State of the Union, and equal push back on the need to avoid antagonizing the "mainstream" and "Blue Dogs" to get economic reforms through.
Bottom line is to expect RFMA not to pass this session, which is fine. Most bills take several attempts to get through. But with an actual Bill as a rallying point, it is possible to focus activism where it will do some good and advance the agenda overall.