By early March 1941, General Wavell knew that the German plan was to send two armored divisions to North Africa (Libya). He was telling people that due to shipping limitations and the upcoming hot weather that he did not expect the German force to be a concern until late summer. The British did not bother to warn the Australian government about the new threat to the 9th Australian Division. The British were focused on Greece, which from the beginning, seemed like a mistake. Anthony Eden had pushed for the Greek expedition for political reasons, not because it was a good, military idea.
The first German division to be sent to North Africa was an improvised light motorized division, the 5th Light Division. The division had been formed with a nucleus from the 3rd Panzer Division. The initial plan was for a unit similar to a British armored division support group, but the plan was changed to something more like an armored division. The division would have two armored battalions created with light and medium tanks. Hitler decided early in the process to send a complete armored division in addition, later in the process. Rommel was appointed commander on 6 February 1941. Convoys started sailing from Italy bound for Tripoli. There had been a concern that the British might advance to Tripoli and create a problem for disembarking the new division. The British stopped their advance a the frontier between Cyrenaica and Tripolitania, so that was not an issue.
As for the Italians, they had four weak infantry divisions of six battalions each, all of them lacking artillery. There was also the 132nd Ariete Armored Division. The Ariete Division had some 80 tanks, but no anti-tank guns. The 102nd Trento Motorized Division was being shipped into Tripoli, but was still partly in transit.
The 5th Light Division would have tanks, infantry, artillery, anti-tank, and some anti-aircraft artillery. There would be 150 tanks, many of them being Pzkw III or IV medium tanks. The anti-tank guns would include both the 50mm PAK38 and 88mm guns. The German armored cars included some of the 8-wheeled type that were much stronger than the Marmon-Herrington Mk.II's of the King's Dragoon Guards. This is based on the account in Vol.III of the Australian Official History.