Understanding R/T is something that takes time to build up. Ane fule kno's that.
A sim is in no way shape or form a good experience building place to learn it.
It shouldn't take someone long to work it out, but most "traditionally" trained CPL's will have an advantage over someone with naff all experience of real ATC in a dynamic environment.
They might still be rubbish at it, but they are one step ahead.