Hero:

Looks like in the British campaign the Vigilant heroes are given out almost as often as Provocator. At least this time it was combined with less powerful other abilities. My Cruiser tanks could use this hero to access all sort of vulnerable targets and still b able to fall back to formation.

This hero is just silly, three top-tier abilities on a single unit? I assigned him to the Humber AC regiment to not go too crazy with the power level.
New Units Commissioned:
3rd Armoured Car Rgt., RAC - OS11 - Morris CS9 LAC
Since the air force had to be benched this time, I got one more recon car unit. This early in the war recon cars are still valid against enemy armor and their mobility in the desert is a major advantage.
New Equipment Provided:
1st Medium Regiment, RA - BL 4.5 inch (Bren Carrier)
I gave this artillery Bren Carrier transports as I finally had core slots to spare.
Starting Prestige: 13287
Starting Army Composition:
Infantry
No. 1 Commando - OS20 - Commando (Bren Carrier) - **** - Zero Slots
1st Field Company, Royal Engineers - GB Engineers (Bren Carrier) - ***** - Provocator
2nd Field Company, Royal Engineers - OS17 - GB Bridge Eng (Truck)
1st Infantry Battalion - GB Infantry (Bren Carrier) - ***
2nd Infantry Battalion - GB HW Inf (Bren Carrier) - **** - Fearsome Reputation
Tank
1st Royal Tank Regiment - OS11 - Vickers Mk.VI - **** - Artillery Support, Butcher, Steamroller
2nd Royal Tank Regiment - OS12 - Cruiser MK.IV - *** - Double Move, Entrenchment Killer 2x, Flag Killer, Ignores ZOC, Steamroller, Vigilant
3rd Royal Tank Regiment - OS12 - Matilda II - *** - Avenger, Entrenchment Killer 3x, First Strike, Provocator, Rapid Fire 1.5x, Steamroller, Vigilant
4th Royal Tank Regiment - OS15 - Wasp MkIIC - ** - Steamroller
Recon
1st Armoured Car Rgt., RAC - OS15 - Humber AC Mk.I - ***** - Double Attack, Overwhelming Attack, Provocator
2nd Armoured Car Rgt., RAC - OS11 - Daimler Dingo - ***** - Butcher, Double Attacks, Lighting Attack
3rd Armoured Car Rgt., RAC - OS11 - Morris CS9 LAC - *
No. 1 Long Range Patrol Unit - Chevy-WB - ***** - Legendary
Anti-Tank
1st Anti-Tank Reg., RA - OS13 - Bofors 37mm AT Portee - ** - Double Move
2nd Anti-Tank Reg., RA - OS11 - OF 2 pounder (Bren Carrier) - *
Artillery
1st Field Regiment, RA - OS15 - QF 25 pdr (Bren Carrier) - **** - Double Support, Expert Support, Famous
1st Medium Regiment, RA - BL 4.5 inch (Bren Carrier) - ****
2nd Medium Regiment, RA - BL 6 inch 26 cwt (Lorry) - **** - Skilled Support
1st Heavy Regiment, RA - BL 7.2 inch (Lorry) - ***
Anti-Aircraft
1st Light AA Reg., RA - OS12 - Vickers AA - *** - Skilled Support
2nd Light AA Reg., RA - OS12 - 20 mm portee - **
3rd Light AA Reg., RA - OS12 - 40 mm SPAA - *
Reserve
No. 1 (Fighter) Squadron RAF - Hurricane Mk.I - **
No. 2 (Fighter) Squadron RAF - OS11 - Gladiator Mk.II - **
No. 3 (Bomber) Squadron RAF - OS11 - Wellington Mk.IC - ***
No. 4 (Bomber) Squadron RAF - Stirling Mk.I - *
Highlights

I moved most of my army directly west to block roads and to fight any Italians encountered, preventing a flanking attack on my bridge engineers.

A much smaller force served as an escort for the engineering units. They moved northwest, the shortest route possible due to lack of truck transports.

First enemies found and stopped. I took my time and did not push west too aggressively, as my position was well defended by rough desert an other terrain features.

When the army reached Mechili, it effectively blocked the Italian capability to counterattack. I slowly begun to target enemy tanks as required by the mission objectives.

Engineers and their escorts reached the road to Derna. It was guarded of course, but not by forces strong enough to be any major threat.

Enemy tanks kept running into support fire, be it due to Provocator heroes or simply bad weather obscuring visibility.

It turned out that Italians did have a surprise in store, as some of their forces attacked north of Mechili, using their own bridge engineers to cross the river. This was unexpected, but since at this point the core of their army has already been defeated, it contributed nothing to the overall situation.
Summary
Final Prestige: 13097 (down 190)
Overall
Some prestige lost this time mostly since I did not have many opportunities for capturing units or locations. The map made most combat encounters about destroying Italian units directly rather than attempting to encircle them, so the gains per turn never quite covered the losses taken here and there. The attack on Mechili wasn't too complicated, but the enemies hidden behind the river and using bridge engineers to cross it for a counterattack were a really nice touch and could punish anyone feeling overconfident. Escorting bridge engineers was a bit of a hassle mostly due to their slow movement speed without transports. It forced me to think very carefully about their placement to not only protect them from attacks, but also to not have them block their own paths given how narrow passages through the desert were.