Why are order giants such a popular late game strategy? I find that upgraded archers and speartons are more microable and easier mass without the need of a clumsy transition. Giants being immune to stun and less vulnerable to magikills is a plus, but speartons do fine while stunned and archers can be micro'd away from Magikill attacks. (This does, however, take them out of position and briefly reduce damage output, which is a minus.)
Giants are pretty much needed late game, they are amazing meat shields in comparison to speartons. In late game, you are better off with some giants than some speartons a majority of the time. 1 giant (fully upgraded) vs 3 speartons, you want the 1 fully upgraded giant, it can handle more hits, which is needed in 80 pop vs 80 pop situations.