And during training, you need to replay battles many times, looking for tactics – you can't learn this just by watching streams.
And when defeating the computer at 200% becomes too easy (and therefore uninteresting), you should switch to 160% – it's much more challenging there.
And if you have a map editor, you should create a training map – a fully developed castle (without a guild of mages), several hidden spots, scrolls with spells, and a lot of different objects (tombs, gnome dens, etc.).
And on this map, you can practice with different troop compositions and try to capture objects.