I can't say much for Guinea's or the Geese but as far as I know those Geese Breeds are fairly large, Silkies are Bantam (small) and Polish can be found in bantam and largefowl. Mixing large and small doesn't Usually work out (though sometimes, like for me, it does) Though from what my friends tell me thier Geese stay away from the ducks and they both stray from the chickens so maybe you wont have any issues.
Now, if youre planning to Free-Range your chickens, I would never ever suggest Silkies or Polish, any size. They're both crested (bearded is worse) and they have the most Awful time seeing and looking up. In order for our silkie and Polish to free range with the rest of our girls we have to give them Monthly Haircuts to reduce the size of the crest and beards..
