Keeping chicks and goslings together?

[asopos]

I recently got to look after 2 chicks and 2 goslings. Both are 3-5 days old at max. They like to snuggle a lot. I’ve been keeping them warm when they are not running around in the garden (supervised) and they mostly do all their eating and drinking those times. They only go to their pen to sleep when they had lots of food and water . So I don’t leave water in the cage when I’m not around. Is that okay? How long can they be kept together?

 

[Gallinarium]

Growing birds need water at all times, especially waterfowl, but you can't really say that when they both do. While going without water for a little while probably isn't going to kill them, it's better safe then sorry.
As long as they're bonded, goslings and chicks usually get along fine, and when they're adults the geese often protect the chickens from raptors.
But they can trade diseases, and goslings create wet conditions for the poor landfowl. Additionally, they each need specially formulated food, despite what the feed manufacturers say.
Despite this, the mix usually turns out fine. The adults usually coexist better than the babies, but you don't have to separate them unless you see problems. They can easily share a running space, but they should ideally have separate coops as adults.