A common strategy I have faced that relies on going second is to put a hard defense in the front expecting your opponent won't be able to clear all territories. If you wait for the opponent to fully attack by waiting to the last hour (and assuming your opponent doesn't have that luxury) you can see what territories they cleared and how efficiently they did so. While your opponent likely wasted good teams trying to get through some teams that they ended up failing to beat thus taking in weaker teams to clear other defenses less efficiently, you can ignore the hardest defense teams and focus on matching them on territories while getting better banners per battle.
I've also taken advantage of going second where knowing how many points you need to win at the end informs you whether you need to risk an undersized squad or not.
