I respect everyone's choice. But the Huntress... you chose a Ballista, which will slow you down on the adventure map.

I don't quite agree, there are many nuances.
1. If you don't need the 2nd level on this map for completing the scenario (and that happens), then the Ballista is simply the best option. I'll explain. The accumulated Ballistas on the tower are much more dangerous to the enemy than spearmen.
2. If the map requires many battles near the castle with neutrals to raise resources for building level 3 and 4 units.
P.S. But if you need to move a lot on the map with levels 1, 2, and 3, then there's no argument, spearmen are better.