A weighted average of the three maps expresses the relative importance of each factor to determine overall susceptibility. For example, steepness might be identified as five times more important than either soils or vegetative cover in estimating landslide potential. The weighted average is influenced preferentially by the SL rate map's high rating, yielding a much higher overall rating than the simple average. All that may be a bit confusing. It's Like baking banana bread.
Some folks follow the traditional recipe, some add chopped walnuts or a few cranberries.
By the time diced dates and candied cherries are tossed in, you can't tell the difference between your banana bread and last year's fruitcake. The real difference between a recipe and a model isn't in the ingredients, nor the processing steps themselves. It's in the conceptual fabric of the process. But more on that later.