Look, I will clarify one of those contradictions as the model to follow.
If you are really interested, first verify your source and later come with solid evidence. So far, the link you have posted shows that the author of the article enjoys of lack of reading comprehension.
The first point he uses for his assumed contradiction in the bible:
" "He left not a single survivor" (Joshua 11:8)
Lets see this part.
7 So Joshua and his whole army came against them suddenly at the Waters of Merom and attacked them,
8 and the Lord gave them into the hand of Israel. They defeated them and pursued them all the way to Greater Sidon, to Misrephoth Maim, and to the Valley of Mizpah on the east, until no survivors were left.
Joshua defeated whom? The armies of various kingdoms.
He left no survivors, this is to say, no troops survived the war, they were killed in action and the injured killed as well. Complete annihilation.
Plus, reading a little further, the kings were also killed.
10 At that time Joshua turned back and captured Hazor and put its king to the sword. (Hazor had been the head of all these kingdoms.) 11 Everyone in it they put to the sword. They totally destroyed[a] them, not sparing anyone that breathed, and he burned Hazor itself.
And people from those "CITIES" were also killed, no survivors.
12 Joshua took all these royal cities and their kings and put them to the sword. He totally destroyed them, as Moses the servant of the Lord had commanded.
13 Yet Israel did not burn any of the cities built on their mounds—except Hazor, which Joshua burned.
14 The Israelites carried off for themselves all the plunder and livestock of these cities, but all the people they put to the sword until they completely destroyed them, not sparing anyone that breathed.
In times where agriculture was the main source of work and income, the population of a city was way smaller when compared with the population of the farm areas.
Do you know what is ISIS?
ISIS is the survivors of the Western attacks in the Middle East.
The Western armies destroyed the armies of the invaded countries but the survivors of those troops and families dead by collateral damage have formed their own army and now are counterattacking.
After Joshua died, don't think that the situation in those lands stayed the same.
Like ISIS rose up some years later, the survivors, people from farms, organized themselves to fight back against Israel. At that moment Israel was without a strong leader, to the point that their war strategy was practically improvised.
"Israel Fights the Remaining Canaanites
1 After the death of Joshua, the Israelites asked the Lord, “Who of us is to go up first to fight against the Canaanites?”
The raising up of ISIS took just a few years.
The same happened with Canaanites and other peoples in that land, in a few years they did recovered and populated again the destroyed but not burned cities, they continued their life as farmers. Israel population wasn't that great to control the conquered lands, and additional wars started again.
And I will recommend you to read the bible before using other sources which will lie to you because their authors know that you are a religion hater and that you will never verify what they write.
Use the model given above, and verify by yourself if that link of yours is telling the truth.
So far, it is understood that because your ignorance about the biblical narration, you have been deceived and you are taking sides in base of wrong or fraudulent information.