RR vs. Q

I think the two rooks are better, especially on the seventh rank. Two rooks on the seventh rank can win all of the pawns on the seventh rank, as well as maybe mate the king.
I would aim to win the isolated white pawn without sacrificing either of the black pawns on that side. This is exactly the advantage of two rooks - you can line them both up on the isolated pawn and then the Queen is no protection. Also, the white king is on the wrong side of the board.
From this point of view, you have already possibly made a mistake by not playing Ra5 when you had the chance. Try putting *that* position into your engine.

"An illegal move which can be played" WHAT?
What?!
He means it's a joke puzzle which can be solved by illegally promoting a pawn to a piece of a different colour - which I believe was once not actually prohibited (much as it was once theoretically legal to castle "vertically" with an underpromoted-to-Rook pawn on e8 (or e1)).