The only problem here is that it is psychologically hard to lose a very high xp unit... or a warlod, for that issue.
What is this unit? It's just stronger than the others, but doesn't give you any other benefits - unless you need to build the heroic epic (or the west point).
So why afraid losing it?
I think there are 3 ways to use a general well (apart from putting it to specialist/building):
1) Give him some promotions that work when you aren't fighting (commando for fast pillaging, hight medics for moving hospital, etc)
2) Spread the XP between your units... you get 5 one level higher cavalries and that can make the difference in your next war
3) Create a super unit to attack tough targets (to kill 1st/2nd units in city - which are not injured yet) without fear. If you lose, well be it. But more often than not, you'll win. Saving 5 other units at that 1st city of the AI can make a difference.