Permit me to offer an answer.
Perusing my various ops manuals, B-RNAV is supposed to meet RNP 5. (ie equal to or greater than +/- 5nm for 95% of the time) for European airspace.
The following is what's acceptable.
Mix IRS
DME/DME
VOR/DME
LOC
DME/DME-LOC
VOR/DME-LOC
GPS