I have enough 'early war' infantry, and some early war kit (such as 38mm AT guns) to represent German infantry battalions from 1939-45. But partly because I'd started buying kit for Normandy onwards, and partly because later war kit is more popular among manufacturers, I tend to refer to this army as my 1943-45 army. This is because the main battle tanks are Panzer IVs (the Panzer III being considered obsolete by '43) and Panthers (introduced in the summer of '43). To take it earlier, I would mainly need to equip a tank battalion with Panzer IIs (for '39-'40) and/or Panzer IIIs (for '41-'42).
Elite Panzer Battalion equipped with Panthers and AT company of Jadpanthers
Prior to picking the Rapid Fire rules, I'd already bought 9 PzIV Airfix kits and 5 Panthers (I think Matchbox, which were still around when I bought them), 3 Jadgppanthers, 4 Jadgpnzer IVs, 3 Wespes, a Puma Armoured Car, and 6 Hanomag half-tracks (all Matchbox). I also had a couple of Airfix German Recce sets (with kubelwagen and armoured car) and three boxes of Revell's 105 mm artillery. With the addition of a couple of sets of Armourfast kits which gave me 4 more Panthers, this gave me enough for a Panther battalion, a PzIV battalion and most of an armoured Panzergrenadier battalion, with a couple of spare half tracks. Reading through the various unit organisations in the Rapid Fire supplements, I ordered a set of two Stugs from Armourfast, a set of two PAK 40s from Italeri, and five Opel Blitzes from Ready-to-Roll, three uncovered and three with the cover on. I later also got the Hat sets of 75mm IG and 38mm AT gun (although the latter more to use as a Russian 45mm).
Panzer Battalion equipped mainly with PzIVs (unfortunately some painted pre-'43 grey. Damn!!) and an artillery company of Wespes
I worked out with a bit of swapping here and there (eg. using a Hanomag as an HQ unit for a Panzer battalion or a tow for an AT gun), I could probably then put on the table, up to two tank battalions, an armoured Panzergrenadier battalion, a motorized Panzer Grenadier battalion and several fully equipped infantry battalions.
My main 'faux pas', was the first kits I painted up and decaled (6 Pz IVs). I didn't feel like following the camo pattern on the box/in the kit, and thought I'd do them grey. This was before I did much research, and I was subsequently discovered that the grey camo was dropped in 1943. PzIVs were around before then, but most of the 'grey camo'ed' tanks that rolled into Russia in 1941 were PzIIIs, the PzIV initially being considered an 'infantry tank', and gunned with the short-barelled 75mms (which come with the Airfix kit and I have kept, and have not glued the long barrel 75mm's into the turrets).
One of six infantry Battalion with HQ & all heavy weapons, this one has an assault gun company represented by a couple of Stugs
The hard work was actually getting together all of the different elements to represent such as HQs, forward observers, heavy weapons, mortar, gun companies, AT companies, trucks and tractors in the right numbers. HMGs or mortars, for example, in Rapid Fire usually have 3 man-crews, but most manufacturers only model two with the weapon, so I general made a bigger base and cut the weapons off some figures to represent ammunition carriers etc.. For some reason, mortars are not a popular item for manufacturers to put in WW2 German sets, and I ended up adding a few mortars from a US set, on a large base, with a few extra figures trimmed of weapons, based separately. That way I can always use them with another army.
An Armoured Company of a Panzergrenadier Battalion
The great thing about having all the main elements of the army done is that I have been able to generate a 'scenario' generation system that involves pulling 'battalion cards' and 'reinforcement cards' from a deck, and after a lot of blood, sweat and tears can be sure that I can field any combination of battalions or reinforcements, without finding I don't have the right kit.
Obviously there is always stuff you can add. The German army in contrast to say the Russian, had all sorts of different AFVs. It would be nice to add some gunned support half-tracks to the Panzergrendier battalion, some command tanks/half tracks, an '88' or other AA, some more towing half tracks and/or trucks, a Tiger etc., etc.. But altogether all the essentials are there.
The whole lot!
If I was to extend it in a serious way, I think probably get three boxes of Armourfast PzIIIs to give me 6 models, and some more PzIVs (probably 'Ready to Roll' with 'schutzen'). I'd paint the PzIVs in late war camo, and replace the barrels for some of my existing PzIVs with short barrels, so I could have a 9 tank battalion with companies of two PzIIIs and a PzIV. That way I get to be able to field both a 1941 Eastern Front Army, and get enough PzIVs in late war camo, so I don't have to put the grey painted ones on the tabletop for post '42 battles. After that I'd probably add some PzII's to be able to do the invasions of Poland and France...
PAK 40 and crew