  We compare four-- and five--flavour scheme predictions for $b$-associated
production of $Z$ and Higgs bosons. The results are obtained with \Sherpa's
MC@NLOimplementation for the four--flavour scheme, treating the $b$'s as
massive, and with multijet merging at leading and next-to leading order for the
five--flavour schemes. Comparison with data for $Z+b(\bar{b})$ production at
the $7$ TeV LHC exhibit strengths and weaknesses of the different approaches
and are used to validate predictions for $b$-associated Higgs-boson production
at the 13 TeV Run II.
