- Spidertron, loaded with regular rockets
- Stronger Explosives researched to 12
When firing automatically, Spidertron will shoot two missiles at once for each Behemoth Worm.
It will only shoot one missile with Stronger Explosives 13.
Different phrasing:
When Stronger Explosives 13 is researched, a Spidertron loaded with regular Rockets will only shoot one such rocket at a Behemoth Worm (no more rockets are fired while the first one is in flight). When Stronger Explosives is only researched to 11, Spidertron will fire two missiles at once, because one is not enough to kill a Behemoth Worm. This indicates to me that it was intentional that Spidertron will only fire as many rockets as needed.
However, the threshold seems to be off. With Stronger Explosives 12 only one rocket is needed, but it fires two.