Maybe if Defenders only defended the immediately adjacent unit to its left or right or units both left and right, that would better balance their reach vs simply defending the whole row per se?
Without them, however, I could see a whole raft of cards being simply not worth it because removal is so powerful at taking out cards in one go. Anything at 4 or 5 value that you need to stay alive would be almost impossible without some defence.
More armour is an interesting alternative and upping base levels for key units might help, but then row attacks would need to be stronger for them to create any value whatsoever.
Without them, however, I could see a whole raft of cards being simply not worth it because removal is so powerful at taking out cards in one go. Anything at 4 or 5 value that you need to stay alive would be almost impossible without some defence.
More armour is an interesting alternative and upping base levels for key units might help, but then row attacks would need to be stronger for them to create any value whatsoever.