Yes, there have been such cases, but you mustn't do the training battles (the tutorial), as you are guaranteed to lose a unit to the Green Dragon there. Then it's all about having the resurrection spell and ensuring unlimited supply of mana.
How do you ensure unlimited supply of mana? Get dryads or royal thorns. They'll summon some more thorns. Put all of those away from your and enemy units. Put a wall to block the few remaining enemies. Put lvl 1 poison rain (or something like that was the name of the Sleem's skill) over the summoned thorns and cast magic spring on them. You can get a lot of mana this way and it doesn't cost much rage, which a single inquisitor stack will easily replenish.
As for the rage box, it's not much of a deal. Do the abandoned castle quest in Velarion Forest, which doesn't require fighting, simply some agility. Then do the donation quest in marshan swamp - once again, no fight needed, just agility. Then do the dragontooth tavern quest in Arlania, which also doesn't require fighting. Those 3 will get you started off the right foot. With any luck, you will find some decent HP units in the Dragontooth tavern. You can also get a free boat in Arlania through another quest and do some stealing.
Also be aware that most of KBTL's units have lower health points than their counterparts in KBAP, so stick to high-HP units.
You should check the king's bounty: the legend forum.There are a lot of tips there.
http://forum.1cpublishing.eu/forumdisplay.php?f=93
However, KBTL was harder to do without losses due to the weaker units.
Come to think of it, the original king's bounty will be the hardest to do without losing a unit
