R+2pawns for a N+B Ending

My engine says the position is equal but Black is 2 pawns down. Anyone know why?

I think I'd prefer to play the White pieces here. If white is to move. Rbc8 looks good as one option and maybe a5 (?!). And has a 4:1 pawn majority on the Queenside. 

A5 b5 and I'm not paticularly comfortable as white. But I guess white's plan would be to push his queenside pawns, black has a lot of good looking moves but it is hard to know whether they achieve anything concrete. Maybe your engine has an idea connected with promoting the e3 pawn and forcing white to sacrifice an exchange?

This is the kind of position where the point count doesn't matter a great deal. It all depends on plans and dynamics. Important for instance is the variation in the previous posts 1. a5 b5 with the threat ..b4+. If black loses this option and is forced to play bxa5 then white's passed pawns are awesome.

Instead of looking at the engine's score, this is the time to look at the play lines supporting it. Does the engine suggest a workable approach for either side? Or does it just move pieces aimlessly around? This one might be as difficult for the machine as for the man.

He's not just two pawns down though, is he. Black has two minors for R and 2 (as the title says) so never going to be that clear. No idea who is better here!

Since ... b4+ is a good choice for black, then white has to deflect the knight first.
1. Nc1 Ndf2
2. a5
White needs to get something active.
There is no path to the e-pawn ( K on d4 risk N on f3 fork ). 
It is one of those, if white tries too hard to win he loses.
See for example the move I suggest, it stops the rooks communicating, (a risk) hoping to free the queen's rook.

@Rat1960: That's a good suggestion based on a logical idea! This position is really too hard for me and I don't know how to continue. Probably white is better since it is not easy to set e3 in motion. Really a good time to consult an engine or a GM!