Base expansions and tech transitions as actions are all triggered by certain momentary events. This is simply due to the fact that each of necessary actions for that have prerequisites. And a neural network will simply learn long term strategies as sequences of trigger responses without any actual long term memory involved.
How big is the decision tree for tech? About ~100 nodes total? This is quite small and handling that is not so impressive. That's roughly one move in a mid game chess position (and you'd need to think two or three moves ahead to be moderately successful at that game).
