Even taken at their word, it doesn't change the fact that they are using documentary procedures that are unusual, and abnormal. Contact any business college, or speak to established traders or people working for large multinational corporations. Talk directly to international bankers on this.
The point is that the often_heard notion and claims by some sellers or their overzealous agents and brokers that the use of the LOI to initiate a purchasing proposal by a buyer "is how it is usually done and this is how it should be," may be applicable and prudent only in the minds, the imagination, and hopes or dreams of those sellers, especially the more marginal ones and their brokers and agents who operate on the fringes largely on the Internet. It is NOT a view that is shared by the broad spectrum of credible buyers, more especially when the "sellers" involved are largely unknown and obscure operators.