lucky, I think that a Sea Hunter with 30 AT and 10 DF is better than a Sea Hunter with 40 AT and 10 DF.
Similarly for a Guardian, 30 AT and 0 DF would be a nerf, I think.
Same for Tortoise, 40 AT 0 DF would be weaker than currently.
Can you name a unit where it would be a buff for its DF to be converted into AT?
I'm talking more about SS than units themselves, because SS are a one time thing... and if you're up against a shield breaker or even any sort of penetrating effect, that SS has just gone to waste because the DEF is meaningless.. whereas an attack buff is more likely to be effective, because then at the very least, you can likely kill something on that turn.. which means it was at least as good as a damage SS.