Gram wasn't exaggerating.
Of the over one hundred goblins that had been sent, only fifty remained, and that number was steadily dwindling. On the other hand, of the thirty elven spearmen at the start of the battle, 23 still stood.
The elves this time around were just too disciplined, too prepared. Their spears slipped through the gaps in the goblins' armor more often than not, while the goblins were having difficulty adjusting to their armored opponents.
They were too short to aim for the elves' necks or faces, and anything they managed to do with their halberds short of completely cutting off limbs would vanish in moments as the leaves continued to fall from above.
Even when armed with halberds made for chopping, goblins still only had the strength of children as a baseline. These ones, who had trained for most of their lives, were above that, but they could never hope to match the raw strength of an adult elf.