Personally I do prioritize Laser Drill upgrades though. Both can solo clear enemy waves (reliably in my opinion). On average this is one of these calldowns every 2,5 minutes plus combat drop. I actually wonder how it is possible to lose if the Laser Drill Upgrades are rushed out early.
Also Thors are much more sustainable then Goliaths and more easy to micro in combination with the Hercules and also the Science Vessel (as you mentioned), so they sometimes are the better antiair. Especially when considering Immortality Protocol and that Swann's army is so expensive.
One thing to note is, that Swann's masteries are what really makes him shine. Each of them can have a huge impact.