I still prefer attaching them to my scouts/explorers, at least if I want them to be super medics. They're guaranteed to be attacked last in a stack giving them the best chance of surviving unless you're up against a far, far superior foe. In that case you deserve to lose it.
If I were using my general to make an offensive unit then I can see siege being a plausible choice. Only thing is I probably never would -- much better to use him to make a military academy or settle him in my unit pump city.