It’s hard to do sometimes bc you’re focused on a specific area of fighting, but sending a single scout/light cav/hussar into unexplored portions of the map where the enemy base is can give you valuable info of weak points where you can raid.
Many times they are also focused on the battle site and their eco is free and open
I remember a free for all where it was just 2 of us left and one of the defeated enemies had a market standing so I was quietly trading with it.
My opponent sent one scout into that area by chance and he then destroyed the market.
This information that you get can totally change the game.
Also sending just a few units into a different spot can cause them to divert resources from your main battle site which can allow you to push through!