The advanteg with the radar is to know where your opponents army is heading. basicly its a tool that allows you to react to the enemys forces by sending your army to prevent powergen losses or nodes as we call them.
Exsample: knowing where the main army is very vital same goes for suprise attacks to lone nodes, however it important to match the opponents movements with yours.
if the enemy sends a large army to the top, you need to respond, otherwise loss a lot of nodes and income of course radars can keep an eye on their movements but cant tell what is in that army thats the job of the scout to get the intel so you can build a counter army that can deal with enemys army.
Lastly knowing your opponents weak spots and when they present them self to you is when you gain the advanteg if you are prepeard for it.
the one that attacks with out knowing what he will face will end up in a bad situation and otherwise losses that coulde be avoided is instead given the enemy the advantege.
the most important thing in stragety is to get your opponent to move into an unfavorable position. Thus in strategy it means to take the first step in order to move the opponenet into your plan that favors your outcome.