Agreed. It's been less 'muddling through' as 'being pragmatic', which has a whole different set of associations to the word.
It's not been 'making it up as we go and hope for the best', it's been 'we can make use of this as the situation develops'.
It implies a whole extra level of professionalism and adaptable thinking that the usual narrative of 'we're just clever enough to be lucky' doesn't really apply.
The making it up as we go approach is prevalent in all armies simply because as situations develop you have to adapt to them. For the British army in WW2 the professionalism was always there, as much as it is in any army at least. The British problem in WW2 was that during the first few years of the war events always seemed to come up before Britain had time to properly come up with a plan. This in part was down to industrial and logistical issues they could not control as well as political.
Take the current time period ITTL, the end of Compass and the lead up to the Greek Campaign. In OTL Compass has been finished for only 3 days, pretty much the whole of XIII corps needs rebuilding and Britain isn't in a position to quickly and easily do that OTL. Then the prospect of Greece comes up as things are being evaluated and that changes everything again. All this was made worse by the shoestring Britain was running the war on during this time period.
Now compare that to TTL. Compass has finished a couple of weeks earlier and the XIII corps is in much better shape. That gives Britain a much better foundation to work with moving forward which, combined with the extra time, allows for decisions to be made sooner. This is because the scale of the decisions being made are a lot smaller, reinforcing a force rather than rebuilding it in essence. In addition Britain, while still operating on a shoestring in many respects, has a far more sturdy and determined shoestring. The extra tanks Britain has over OTL alone are a major benefit, that they are far more capable than the OTL tanks only multiplies that benefit. That gives Britain a much easier time making decisions as they have not only time but also pieces to play with, something they lacked OTL.
The whole affect is cumulative. More time to make a decision leads to better decisions being made generally. More equipment to allocate to the forces means decisions are easier to make so less time is wasted making them again leading to better decisions. The extra freedom this is granting commander means more time can be spent on the smaller details, again improving the force as a whole.