Probably not because with county & England you manage both teams at the same time which also I think is the purpose of the game to see how well you can do with coaching two teams. But instead if you say tried some other teams like SL, Pakistan, Ban, India , those teams usually only have matches after the county championship, usually none during the county season, so you would only be managing the 2nd team after your done with the first one most of the times which isn't how it's supposed to be. Don't know if this makes sense tho.
But even if you try to change them, you can't really see England in the hex editor, so it's difficult to know what to change. It might be some value there that determines the international team that you would have to change, maybe?? I've never tried but try changing some values close to the county team, one of them determines the difficulty level( I think the 6th one so you would change that to change the difficulty , I think 03 is normal, 01 is easy but if you're not sure you can usually compare two games one on easy, one on normal to find out), so maybe change something else, usually it would corrupt your game so you would have to undo the changes, but maybe change each value 1 by 1 if you have time but very unlikely it will work I think.