What they wanted was PzIVs supporting PzIIIs of course.
Looking at their substitutes the Pz38(t), Pz35(t) and PzII seem to be close enough, in descending order, to being able to do the job allocated to PzIII but none of them very convincing for HE or Smoke. What did the Germans do to support them?
Take them as substitute PzIIIs and allocate PzIVs in ratio to the grand total?
Allocate something else? If so, what?