Hi, thanks for your report, We have answered this in the FAQ which can be found here
The cooperative campaign is designed and developed for cooperative gameplay in the spirit of the experiences of our MACV-SOG veteran advisors. Already in early testing, it was very clear that any attempt at running the campaign in single-player with AI would not at all reflect these experiences. Unable to change the AI we decided to stay true to our veterans and NOT market the campaign as a single-player campaign with AI.