Hey Kandel, you know, it's an old question about SP/COOP official support for the latest maps. The main issue is to program ai to perform a minimum decent combat behaviour. This thing looks quite challenging, frustrating and time-consuming sometimes, as often reported by the devs.
But you can try the non-official support provided by the community, like Darman's packs and garylee's Ogledow. They are quite good, and with them you'll have most of the maps working in SP/COOP.
The only ones not covered yet are the latest Finnish maps (Ihantala and Tali), but who knows what can happen in the future? Matthew said someone in the team is likely working on offline support, so patience is your friend by the minute.
By the way, good work to all the team for the latest patch. Content is just marvelous! Keep up the good work gentleman!
Warmest regards,
batistadk