1) My argument is simple: the USA has to keep the bulk of its troops in the Confederacy. The Confederacy is the size of Western Europe. The USA does not have an inexhaustible amount of manpower. The Union Army, in occupying the Confederacy, produced a leadership class as undistinguished at best and incompetent at worst as its CS counterpart. The Union Army has no preparation to fight European armies from fighting the incompetent conscript Confederate army. Thus, in a British invasion the British will not be fighting any significant number of US troops, and will have a bare minimum of competence the CSA's forces never had at any point.
2) And what of the Second Opium War?
3) My evidence relies on the historical reality of the Confederate Army. It's no co-incidence that all positive statements rely on the Virginia theater, as this is the only one where the CS Army was able to produce Pyrrhic tactical victories that all wound up being in the long term strategic defeats. In Virginia the CSA had favorable geography, it had a functional cavalry arm where McClellan did not, and unlike Hooker and Burnside it had an overall balanced structure and leadership team....until Lee's very aggressive style of warfare started degrading that army and until it had to actually fight a sustained style of warfare that rendered it irrelevant in six weeks for the duration of the war strategically and to a much greater extent than generally given credit for tactically also.
And this is the Virginia theater. If we start discussing the CS Army in the West, it's a question whether this is tragedy, farce, or tragifarce. The CS Army in the West fought hard, but nobody who accused Bragg, Johnston, Pemberton, AS Johnston, Price, Van Dorn, and so on of brilliant leadership would find enough to indict any of them. The most damning comment about CS leadership in the West/Trans-Mississippi is that its most brilliant guy was a division commander.
4) And that worked so well for Russia in the Crimea, did it? Your argument is that quantity = quality. Quantity does not in fact equal quality in any sense of the word. The Union didn't win that war with simple quantity, in fact Grant was one of the most frugal generals on either side with human life. Human waves are self-destructive as far as tactics go.
5) "Large scale CIVIL WARS". I assume that the Napoleonic Wars and Sepoy Mutiny and the like were not, in fact, civil wars, right?