@scout thing: It becomes a slave scout but with no defects. It acts like a normal scout but you can see that it is foreign if you right-click.
When you lose a scout, you say it's a lost unit. So if you gain one, what would you do? If anything, you'd decrease your unit lost count, right?
Actually, now that I think about it, if your scout is captured; you lose 1 in the win section and gain 1 in the lost section because the AI has 1 more unit due to your warfare against them and you have lost 1 due to the war too.
And if its killed, then simply 1 is added to lost. I believe artillery could work that way too. It's more accurate after all.
Whatever. Short rush if you must. And if you do it, try to spread out the rushing. Each town can (effectively) take about 1 rush every 20 turns, as you all know, in despotism. Or if you want, use a punchbag town that grows quickly. Once it can't, let it wait and build another close by that will do the same. (just don't abandon them!)