Smooth transitions between organic shapes

Hi all,

For an awesome little project I’m having troubles combining these organic shapes and getting a smooth, organic transition between the solid bodies. All bodies are made out of Lofts with guide curves (G.jpg). I can’t get any of the fillet tool options to work for me. I always end up with tiny numbers.

There are a lot of basic organic shape tutorials online but none address this problem. As a self-taught modeler I might not be aware of all functions that might be useful for this problem. Maybe someone can point me in the right direction?

Thank you in advance.

[EDIT, file added]

SolidworksSurfacing