Would not the greater butterflies be potentially (I emphasise) in the following:-
1) The extra time in France means more Allied (especially French soldiers) end up in Britain.
2) At best, no Battle of Britain, at worst heavier Luftwaffe casualties due to a stronger RAF and weaker Luftwaffe (some great discussions about that earlier).
3) Given the greater French presence on Britain, Somerville is given more freedom of action / time at Mers El Kebir.
4) Enough modifued A12s and Valiants around to make Compass the curbstop that reaches Tripoli.
5) Enough armour in theatre to hold Crete.
6) Liberation of French North Africa and return of France to the fight in 1941 (especially if as previous posters theorised, there might be no Rommel)?
1) Not very many more I shouldn't think.
2) As was explained to me, the Battle of Britain was more than just the attempt to suppress the RAF, so it still goes ahead.
3) Possibly, though I'm not sure it would have a significant effect on the outcome.
4) Definitely not. They might get as far as Sirte, but I doubt they'd have the logistics to get any further.
5) Likely.
6) Doubtful IMO.
Assuming Rommel still leads Operation Sonnenblume, the first potential change comes at El Agheila and/or Mersa Brega. If the British can hold the Germans off there, they effectively blunt Rommel's eastward drive, which will completely change how things go compared to OTL.
There are still a lot of ways things can go. The North Africa campaign could still be a long one because when Rommel attacked the British they were at the end of a long supply line, lost half their stuff for Crete and were in dire need of equipment refits. The other side of that arguement is that if the Germans get enough of a pasting in France, they may not have enough stuff for the Africa Korps. Not enough trucks, tanks, artillery or supplies.
Well here things are different for several reasons:
1) The Valiant replaced the Valentine, and, mixing Infantry Tank armour with Cruiser Tank speed, is a much better tank for it.
2) The Valiant has started production several months earlier than the OTL Valentine did, so probably a few hundred more at least are available.
3) LMS will be producing Valiants, not Covenanters, so production will be even higher, especially if they start a few months earlier, since the Valiant is a proven working design.
I think that will give the British the resources they need to both hold Crete, and also force Rommel back. That will significantly improve the British position, maybe even enough to allow them to shift forces (including tanks) East to blunt the Japanese offensive in Malaya.
Actually, the engine deck remained exactly the same between the tank and the gun tractor. The difference was in the PTO to the cooling fans and the change in the airfilters. The taller body was to accomodate the crew and the ammunition for the gun they were towing.
So they changed the air filters and fans, which kind of makes my point that it's not built the same as the tank, so it's not fair to compare it.