Favorites in battle! - 5 The Battle of Favorites! - 5

I haven't used this technique in a long time because it's forbidden in offline games, and I can't be bothered with it in online games. In WoG, it's very simple, and everyone knows how to do it. But in SoD, it's a bit more complicated. If I remember correctly, when heroes meet, and they only have units with 1 attack, you need to do something with the Split key. I think it has to be done in the original SoD, without HD, because it seems like they fixed it in HD. I don't remember exactly.