My deba has been used for fish only, except the one time I cut a piece of bread with it, which worked really well. I would use my gyuto for a pumpkin probably.
I used mine on a melon, just to see what it would do. Only fish since then. If you want a heavy knife for bones, get a Western deba.
My deba is only for fish. I really dont understand how you would benefit cutting a chicken, duck, goose what ever with a deba.
I really wanted a Deba because they just look so cool. For cutting thru chicken bones and turkey bones.
From what I read, this type of knife chips easily when hacking thru chicken and turkey bones so I decided against it.
I'm now using an old 6" Henkles Chef's knife that I stopped using for everyday chopping.
I'm not sure what the best knife is for this task (spatchcocking a chicken/turkey) but I do it regularly.