Most of the interesting physics at the LHC involves final states with hadronic jets. We present new Monte Carlo event generator configurations used by the ATLAS experiment to model multijet, boson plus jets and Vector Boson Scattering processes in $pp$ collisions at 13 TeV at the LHC. The different generators are compared to each other and to 13 TeV ATLAS measurements in kinematic distributions sensitive both to the kinematics of hard process and to the effect of shower and non- perturbative effects.