9Sonnenblume:
I do really like this scenario and having such a huge map to defend offer a lot of tactical opportunities...
But, depending on how it's defended it may be a little
too easy, as in my playthrough where at the middle of the scenario both German and Italian land forces have mostly been destroyed entirely!

(
Played on normal difficulty, i.e. level 3, as usual.)

I went for an aggressive defense (
as often in similar situation 
):
1. Defend Benghazi and its AF!
The enemy have several AFs near El Agheila and that's it! They have a lot of planes, including many bombers of course, but the map is big and they need to capture some AFs to move forward without fuel issues... So, the idea is to keep their planes away of my land troops by preventing (or at least delaying them as long as possible) from taking another AF. So, Beghazi IS to be defended!
I've deployed there the heavy infantry unit, an experienced tank unit, one AT, one experienced regular infantry unit, one AA unit to cover all. These units, together with the aux Australian infantry unit, it was enough to stop and crush the German attack, including destroying all their armored units... Well, with the help of some of my planes, of course, like the aux bombers we recieved thanksfully, but not all of them as there are Italians not to forget either...

So, a half to say hello to Germans and the other half to harass the Italians...
2. Retake initiative & set a trap!
The basic idea here is to try, using fast-moving armored units, to outsupply several Italian units while they're moving through the desert... So don't just wait them near Tobruk to fight the main fight here, but instead leave Tobruk and it's defenses (several bunkers) to fight in the desert, thus keeping Tobruk's defenses only for a last stand if things don't go well in the desert (some Aussies are expected towards Tobruk as reinforcements anyway).
A. The 3 British Indian infantry units have been ordered to dig in around El Mechili, while the 2 Australian infantry units and the colonial infantry unit have been put near Segnali and Bir Tengeder... so these 6 auxiliary units have moved to take their positions (near rough terrain, easier to defend) and cover/block a wide area, the time to see how things evolve, where the try to push.
B. Mobile team: 1 Vickers + 1 Lanchester + 1 Daimler Dingo units (only the Vickers tanks being able to capture hexes and thus really to outsupply) deployed near Bir Tengeder, then moving directly SW along roads... before being put at rest to let the enemy advance. A little alert when enemy bombers show up; they dispersed and let the Daimler Dingo trick them away from the main goal... well, anyway... After this, they waited a little SE of the town of Msus that the Italians have taken...
The Italians moved straight NE from Msus, in a single column, several hexes wide... followed by 2 units of British bombers... my mobile team move then closer to the undefended town of Msus... once the Italians have moved too far away for being able to turn back against the mobile team, Msus has been taken and directly almost all the Italian troops directly outsupplied!
The bombers were really effective against their transport trucks, the mobile team was engaging the pursuit, the Italian efficiency was going down really fast (being outsupplied!)... fast enough that even their tanks didn't engage the British Indian regular infantry units entrenched when being enough close...
Then, with 6 infantry units, the mobile team and the bombers... well, it was a pure slaughter!
Then, the second half of the scenario was mainly about dealing with enemy aircrafts (and their few land reinforcements), setting traps, making good use of the AA unit, etc.
At the end of the scenario, I had 5 auxiliary infantry units entrenched near Agedabia (in range of enemy bombers from their starting AFs) and covered by my AA unit...
And my own auxiliary bombers where massively bombing these AFs, the enemy having no more fighter or almost...