First you'll need to reach the battle of xuchang, and this is where timing gets crucial. Play as sima shi but when he suggests the pincer attack, ignore that completely and take the western mountain path instead - the timing here matters because you need to reach wen qin before his son wen yang shows up in the central area. The precise sequence is defeating wen qin first, then wen yang, which triggers some specific dialogue and changes the battle flow.

For the battle of new hefei castle, positioning becomes really important. You'll want guo huai or sima zhao here, and you need to watch all the gate positions carefully. The enemies follow specific attack patterns targeting different gates, so you'll need to coordinate defense timing with your allies. Each gate has particular vulnerability windows, so try to anticipate where the next push will come from.

Once you've handled those battles correctly, there's a specific trigger point when you talk to wen yang - this conversation has to happen at exactly the right moment in the stage to unlock the alternate route. The timing window isn't huge, so make sure you're tracking your objectives carefully. After that, you'll go through some hypothetical battles where enemy patterns and positions are completely different from the historical route. Some objectives need specific characters like guo huai blocking xiahou ba's escape path, so watch your character selection timing carefully. You'll want to check the battlefield info screen before each stage to confirm you're hitting all the right marks in sequence.

Just remember the star objectives need perfect timing and positioning, but you don't need to worry about difficulty settings unless specific stars mention it.