Salisbury would provide the English with strong leadership, but he would still be in a precarious situation. Bedford had rejected an offer from the city of Orléans to surrender to Burgundy, and this had temporarily alienated the duke. Burgundy's subsequent withdrawal from the Loire campaign left the English severely undermanned both at the siege and at various defensive positions across the region. The English simply lacked the manpower to adequately defend the territory they'd conquered without Burgundian support. This had at least as much to do with the French victory at Orléans, and the campaign that followed it, as Suffolk's leadership.
That said, if Salisbury
does manage to successfully defend against Joan of Arc at Orléans, then the whole course of the war shifts. Bedford had rejected the offer to surrender because he thought the terms were too generous and that the city was set to fall in the near future. Under the rules of war at the time, taking the city by force would allow the English to sack the city.
Orléans had tremendous importance to the dauphinist cause. Its strategic position would have allowed the English to project power across the Loire and strike deep into Armagnac territory in the south. It also had huge symbolic value as the capital of the duchy of Orléans, given that the duke of Orléans had been at the head of the Armagnac faction for more than a decade before Charles became the dauphin and took control of the party. Indeed, it was a widely held opinion at the time that Bedford would conquer the whole of France if he could take the city. The threat was so severe that some figures within the dauphinist camp were advising Charles to flee to Scotland at the same time Joan made her way to Charles's court.
So, if Bedford were right that the city were close to falling, and if Salisbury could throw off Joan, then the city falls and Lancastrian France may well be born. (I believe this is the most likely POD for an English victory in the Hundred Years War, as
@CaptainShadow well knows.)
@material_boy can correct me if I'm wrong but wasn't policy keeping people alive in the Lancastrian phase?
Especially given she's a woman. Heresy is possible though.
Yeah, I think she'd just be given straight over to the church. A woman in man's clothes talking about hearing the voice of God and all that ...