Stats appear to favour the holder of the two minor pieces.
On the 1400 DB. (with over 1½ millon games a good base
for reference as it made up with games played by the lads
who read these Forums and some think this exchange is OK for the Rook).
Searched for games Where one side has just a Rook,
other has Bishop and Knight. (and of course Kings & pawns).
White has the Rook. 2342 games
White Wins 796
draws 371
Black Wins 1175
Black has the Rook 2205 games
Black Wins 733
Draws 390
White Wins 1082
Of course the pawns matter and the
Bishop and Knight must work well together.
But overall it does indicate a + for the Bishop & Knight.
Wins for the Rook in R v B+N at the lower level usually happen when one of
the minor pieces gets picked up by the Rook pulling off a tactical trick.
The minor pieces have to be careful about settling
on unprotected squares and always be on the alert for
Forks, Pins, Skewers and Harpoons.
1.Rc3 is a standard Rook Fork.
1.Rb8 winning the pinned Bishop.
1.Rb8+ Skewers the Bishop.
1.Rc3 is what I call a Harpoon.
It is neither a Pin (weaker piece pinned to stronger piece).
Or a Skewer (The stronger piece moves exposing the weaker piece).
A Harpoon fits the bill.
A basic attack,check and Rook Fork.
1.Rc3 N any 2.Rc8+ then 3.Rc7+ and 4.RxB
Also the minor pieces have to be wary about getting
too close to the enemy King.
1.Ke6 is a King fork
Then there are Rook sac tricks winning the two minor pieces.
1.Rc8+ and 2.Rxc3 or 1.Ra6+ and 2.Rxf6.
All these tricks cropped up in games I looked at on here.