the questions remain":

" How is it possible in a so called decentralized market, where the exchangers are(should be) independent entities, ALL of them to have the same price when they certainly don't have a "the same" order book(same clients, same orders) ? How is that come? "

I saw many example when the chinesse exchangers dropped or raised the price and all the exchangers did the same without any valid justification. Their orderbook was the same.

The price is artificially created not by users but the exchangers according to their interests.