your opponent's lookout and militia were probably mistakes, and the highway was definitely wrong. The only way to make highway work would be HT, which doesn't really work at all without draw (jack is terrible draw for this kind of engine), and just two buys aren't enough to make the highways worthwhile anyway. Lookout is nice with draw-to-X engines, but there's no payload for an engine here, so it's very likely wrong. The militia doesn't double-jack much at all, especially with plazas (you were slightly lucky to have jack in hand every time plus plazas all but once).
I'm not big on Explorer here either. Maybe one after you've got two provinces?