Military strategy is not something I am familiar with at all. As I listen to my 13 year old play video games where he and his friends coordinate strikes and raids to overtake alien territories, I have no idea how to interpret their moves, motives, reasoning, or objectives. The only part of the missions I understand is that when it goes well, he's celebratory in his response, and when it doesn't, he's not.
That said, I do have enough common sense to realize that marching around your intended target, blowing horns, and carrying a sacred object, is not your typical attack plan. I can also assume that demonstrating this same behavior for 6 days would tip off your enemies to your behaviors and would increase your chances of facing an ambush. Further, I can reasonably guess that doing mostly the same thing on the 7th day but for a longer period of time and adding a shout is not likely to make anything significant happen. That is unless God tells you to do these things. In that case, you're pretty much assured of a positive outcome.
I don't know God's logic in this particular strategy to deliver Jericho to Joshua and the Israelites. But I'm not called to know it, understand it, explain it, or analyze it. My only responsibility is to believe in faith that if this is the record of the attack, the 'black box recorder' of the event, then this is the way it happened.
There are many times in Scritpure we are told to do things that are counterintuitive. If someone slaps your cheek ~ turn and offer the other, pray for your enemies, lose your life to gain it, etc. But probably the most challenging, and rewarding, is the one that says: Follow Me. Even when you don't know where I am going, why I am leading you there, or what I am planning for when we arrive. Just drop what you're doing and come along. Oh and by the way, it won't be easy, you'll have to trust Me when you can't see, and the likelihood of people giving you strange looks is pretty high. The only thing I can say is that the payoff at the end is beyond what you can imagine.
Doing things God's way in our world goes against most of what modern culture teaches, expects, or thinks is best. But we are told His ways and thoughts are higher so why we would ever trade the truth of God for a lie?
Several times before this account, Joshua is told to be strong, courageous, and unafraid. He is repeatedly reminded that God is going with him wherever he goes and that he should be encouraged as he moves forward in his leadership role. We have those same expectations and promises upon us. The only difference between Joshua and us is that we hold the entire story in our hands and can look back to see God's faithfulness and allow it to propel us forward.
Jesus, help us to see more from your perspective. Not the details but the goal to have our faith built up through the waters You will carry us through. Strengthen us so that we don't grow weary in doing what is good, remind us that our hope will not disappoint, and that what You have started, You will complete. In Your powerful name we pray. Amen