The cover story in The New Statesman is The "Three Brexiteers" sub-headed "Does anyone know what Brexit mean" and gives an insight into how the three differ. It's is long and detailed and will certainly tell me more than I have known about these three who have really registered very little other than to be annoyed by Boris's buffoonery, remembering Fox's resignation and, with no real evidence I admit, finding Davis rather shallow.
It does say:
Fox asked to have "economic diplomacy" moved to his department in a "rational restructuring". He had a point. He has no responsibility for securing Brexit - that lies squarely in Davis's department - but until it is accomplished he cannot usurp the EU and make definitive trading arrangements with other nations. he can, however, hold preparatory talks with his American friends and others (he has just visited India) That does create an overlap of economic diplomacy, so one presumes the arguments between Fox and Johnson have only just begun. Fox claimed his acquisition of these powers was "crucial to the delivery of objectives I have been set by the Prime Minister.
May slapped him down, to the amusement of Johnson partisans, but Johnson had to second some officials to Fox's department
The article is here