Is increased Lethality Rate any good?

The Destruction - Lethality Boost tactics card, and the final Siege to Seize tech, increase troop kills. This doesn’t look like it would help win a fight, just serve to punish your opponent. If you aren’t powerful enough to guarantee victory nearly all the time I’m not seeing the appeal. A tactics card that increases attack/defense seems better. Is there a good use for this ability if you’re a mid tier player?