I think a lot of people finish one career and start another from that time. It's a good way of working through to the end and reaching those moments when it becomes a bit harder, like the increase in allied air power in 1942 (iirc). It's something I always said I'd do, but only did it a couple of times before I'd lose a save and I'd think 'sod it - back to the beginning!'.
It's certainly better, and more realistic than going the whole way with just one guy!
