Hello everyone! I need an advice on how to create one particularly complex surface, what method to use, maybe some guides to watch. Basically, I need to connect simultaneously 3 small faces at the bottom with one big face at the top. The problem is I can only connect them separately, 1 small face to a big face at the time, and the end result is a mess. So, I've been thinking that I probably use a wrong approach and maybe there are another ways to get the shape I want. I would really appreciate an advice on how to create this surface.

The model I use for references can be found here (Logitech MX Master|Autodesk Online Gallery ), it's the bottom part of a mouse.