Use the trainer to learn the game, then turn it off for the main campaign. Alternatively, keep it for custom skirmish maps where you want to roleplay as a nearly-invincible sultan.
Unlike the base game, the "Extreme" version features outposts that automatically spawn units. Exclusive trainers often include a "Freeze AI Outpost" feature, which stops the constant flow of enemy units, allowing you to focus on building your castle without being under siege every 30 seconds. stronghold crusader extreme hd trainer exclusive