I really don't expect vicky2 to be a whole lot mroe complicated than HoI3, even form an AI POV. Conducting war requires some rapidly shifting goals and objective, flexible strategy etc. Vicyk2 is more complex economically but the goals for the player and AI are more straightforward...Like I said though, its still a very different game, with more straighforward objectives. Conducting war is much more nuanced than industrialising your country IMO.
How is a 19th century war so hard for the AI compared to proper running of the Vicky economy? The HoI3 AI can fight decently*, but it cannot run its sliders, trade or properly attain raw materials for its economy. Using this engine to manage Industrialization seems far more difficult than running a war, at least with the recent PI track record (Clausewitz engine).
*not optimally of course