I love my geese but they can kind of pester chickens in a confined space and they can be more messy. I had some extra roosters who were in an aviary enclosure with some geese and the geese started to nibble their tail feathers to shreds while they were roosting.
It might work better to have a separate shelter for them, but they can free range together alright.
My personal opinion is that upland birds (chickens, turkeys, guineas, etc) and waterfowl aren't compatible in terms of roosting/sleeping or in small enclosures. The waterfowl are far too messy with a much more liquid dropping. It's not healthy for either type. They can certainly share a large daytime space as long as they don't harm each other.
I keep my 3 week old brown Africans in with my younger chickens just for the night, then let them out to range around the yard during the day. They get along with the chickens most of the time since they have been raised up with them, but if the chickens crowd them too much, say at the waterer or if I throw some feed in, they will grab the chicks by the wing or tail and give a good yank. I also have some Pekin Ducks in another pen, and I plan to move them in with them when they get a little bigger. I don't trust the ducks enough to put them in there yet. I have put them in with the ducks a few times during the day, and although they have not been aggressive toward the goslings, they won't have anything to do with them. I just do not want to take a chance that they may decide to hurt them since the geese are not even half their size yet.
But I do agree it is probably best to put them in a separate coop than in with the chickens. Especially since your chickens are much bigger and may harass them. My older chickens like to pick on them some even when free ranging. I expect that will change in a few weeks though since they should be as big or bigger than they are.