The difficulty you choose for the AI is a very important factor, but not the only one, other factors also play a role. In Squad Battles you can check the opponent team before starting, to see their strengths and weaknesses, so you can prepare better for the match. So the style can change, sometimes they’re compact in defence, sometimes they press hard the whole match, other times they just launch quick counters with rapid transitions, and it depends a lot on the strength and speed of the AI’s squad. Also important are the chemistry and the raiting of the team.