Hi, you dont have anything to worry about. It seems to me like they are suggesting he has a different parenting style to yourself . Also they will dismiss parent alienation and he is making thing worse for himself. You are allowing contact also which rules that out 100 % and you are merely showing concern like any mum would.
At final hearing its likely that contact will remain how it is , what your ex may benefit from as well as contact continuing as normal is a parenting course .
Parenting courses are useful and also may alter his parenting style a bit ie shouting and smacking them . It seems to me like children want to see their dad and generally enjoy it , but not how he addresses things when they dont behave if you know what i mean.
Parent alienation will be 100 % be dismissed and i rather be in your positon at hearing than your ex partners. As long as you are calm, child focused and promoting contact you will absolutely walk the hearing in flying colours . Let me know how u get on