It's funny- It doesn't work on lesser difficulties I tried it on expert and they just don't move like they are suppose to, and since Corrin is absurdely strong, I don't know how to beat him
Hmm, usually when steps don't work its most likely one of two things: 1. Loading into the map with the wrong order then fixing it within the map 2. A unit(s) has some modifications through merging, dragonflowers, supports, etc. If the above isn't working for you, it's probably best to look for a different guide or try using a strong unit like Valentine Lyon + 3 Dancers.