He starts with the other countries holding stretches of the border. Lastwall to the south ("You had the chance to converse with my dear cousin, yes? Imagine if she were far more obsessed with meticulous procedure, and you'll have the right impression"), Cheliax to the north ("One might expect them to be enjoying themselves, given how thoroughly they reject the demands of the Good gods, but instead they seem to have invented new ways to make themselves miserable), Irrisen to the west ("Though they might as well be in Tian Xia for all they communicate with us"). He expects them to be more focused on maintaining their own parts of the line than on supporting the Crusade, though they will need to maintain good relationships with all of them, and they will likely need to cooperate with the Hellknight order holding this fort near the corner when they move the line.
Mendev's neighbors and near-neighbors are next. Numeria, ruled by a madman, which after extensive negotiation eventually agreed to allow crusaders coming through the Worldwound to pass through their territory, unlikely to allow more than that. Brevoy, across the lake, formerly a substantial source of adventurers for the Worldwound, but unlikely to be a major one now considering its ongoing civil war. (Digression about which of its houses are most likely to repay Blai well for it if he supports their faction in the war.) Iobaria, further across the lake, said to be cursed, useful if he wants to recruit adventurers who command the spirits of nature but useless for fundraising.
Other polities likely to be of particular relevance: Absalom, the government of which is unlikely to involve itself but the residents of which include both wealthy people swayable with tales of heroism and adventurers with all sorts of unusual talents. (The Count understands that Iomedaeans aren't supposed to lie, but he recommends that Blai delegate recruitment from Absalom to someone who believes him to have been miraculously chosen by Iomedae.) Taldor, most populous country in Avistan, beset by half-impenetrable factional politics, best approached by appealing to individual noblemen and noblewomen (he briefly summarizes the ones he knows anything about), though their Grand Prince is, ah, overcome by the spirit of charity every couple years, so it's probably worth some effort to make the crusade seem like a good recipient. (He presumes Iomedaeans aren't allowed to deliberately introduce him to appealing so-called vices, in an attempt to make him be overcome by the spirit of charity more frequently.) Andoran and Galt, which are training fewer wizards than when they were under Chelish control, but which had plenty of them when they seceded. (Andoran is experimenting with having its commoners choose its government; reputedly it's essential to appeal to their sense of morality (the Count sounds a little disgusted), though their sensibilities are rather different from those of Mendevians. Their 'president' is a paladin of Iomedae, but his dear cousin doesn't seem to like him. Galt is unlikely to do anything that would make it more difficult for their 'first citizen' to conquer his way through the River Kingdoms. Both will most likely be concerned about the risk of inadvertantly empowering Cheliax's armies.)
—Before he continues, where is the Select from? It may be worth particularly ensuring that his achievements are well-reported in his homeland. (In principle this would likewise be true for his foreign companions, but in practice the Count really doesn't expect anything good to come of proclaiming Ser Seelah's achievements in Geb.)