I picked up the book today. Glad to have it as I really enjoy the challenges of the early war period. I also enjoy the history since the early war forces were still suffering from the lingering hangover of 1920-30 technology and doctrine.
The Pzkw 35(t) was used in 1st Light Division in Poland which became the 6th Pz Division in France.
The Pzkw 38(t) Ausf A was used by 3rd Light Division in Poland.
The Pzkw 38(t) Ausf B,C,D were used by 7th and 8th Pz Divisions in France.
There are probably some other units that used these types. I only know about some of the divisions. This info is in Blitzkrieg as well as many other sources (I found it in the Encyclopedia of German Tanks of World War II). Mixing the 35(t) and the 38(t) in the same kompanie would probably be ahistorical but that has never stopped a
FoW game before.
I'm planning a French unit as well as a couple of German units. The latter are easier for me since I already have many mid-war models. I admit that I'm also tempted by the Polish Kawalerii Zmotoroyzowanej.