Lets assume that as Germany I want to have around 15 Panzer divisions by 1939 for Danzig or war. I also want most of them to be level III medium armor preferably with SPA.
I used to rush the required tank techs and start a X3-X4 production run in 1938 using whatever techs I had researched. Lately in a few games I have been starting a single production line in 1936 of Panzer I, and use the extra IC gained later in the game to upgrade them. Most of them will be fully upgraded by 1939 and I'll have about 15-16 Panzers most with SPA. Even if not fully upgraded they are still effective enough on the ground.
I used to rush the required tank techs and start a X3-X4 production run in 1938 using whatever techs I had researched. Lately in a few games I have been starting a single production line in 1936 of Panzer I, and use the extra IC gained later in the game to upgrade them. Most of them will be fully upgraded by 1939 and I'll have about 15-16 Panzers most with SPA. Even if not fully upgraded they are still effective enough on the ground.