Given how there is no solid source on any numbers, good luck going in detail about their numerical advantage. Especially in light of Orcs alone (better yet, just those in interment camps) being numerous enough that Blackmoore planned to overthrow the entire Alliance with them. And succeeded in the alternate timeline where he stopped drinking. Admittedly it was after Gilneas, Stromgarde and Quel'Thalas already left, but on the other hand Lordaeron was still in it and it was the strongest nation that has ever been a part of the Alliance. Or in light of the Horde demolishing the Alliance at pretty much every front during the previous faction war before the Darkspear Rebellion happened. Or in light of A Good War describing Horde's navy as superior prior to BfA. And given the presence of Goblins in the Horde, good luck going in detail about Alliance's technological advantage. Especially after WoD, where they got Blackfuse's blueprints from the rest of the company that followed Garrosh to AU Draenor.
The Horde also has tanks and guns. The gun siege towers are not even remotely logical on twenty different levels, so you're effectively admitting your going into detail is built upon special pleading and double standards. On top of that Sylvanas destroyed one with an explosive arrow. On top of that other top, there be Azerite war machines. The only Alliance mage of note after Dalaran's latest period of neutrality is Jaina. As opposed to Horde's two mageocracies with at least one magical well (probably two, if the Nightwell is still partially active). In terms of Shamans the Alliance has Nobundo with no real feat to his name as opposed by the Horde who created the Earthen Ring (with Alliance being only allowed to join). And as per the start of BfA, the Alliance reached out to Kul Tiras to balance out Horde's alliance with the Zandalari (on top of their own navy being inferior to Horde's own prior to the war).