what are the similarities between harris and j"s uncle podger?

At the pub, they compile a list of what they need to pack. Harris volunteers to write out the list, and J. compares him for the reader to his Uncle Podger, who always volunteers to help others but bungles the job because he is so accident-prone.

That’s Harris all over—so ready to take the burden of everything himself, and put it on the backs of other people.

He always reminds me of my poor Uncle Podger. You never saw such a commotion up and down a house, in all your life, as when my Uncle Podger undertook to do a job. A picture would have come home from the frame-maker’s, and be standing in the dining-room, waiting to be put up; and Aunt Podger would ask what was to be done with it, and Uncle Podger would say:

“Oh, you leave that to me. Don’t you, any of you, worry yourselves about that. I’ll do all that.”