I first came across this idea in Roger Gard's Jane Austen's Novels: The Art of Clarity. He argues that John and Fanny's conversation in Ch. 2 is very much like King Lear, Act II scene iv where his daughters Regan and Goneril debate about how many men he needs in his entourage and argue from reducing the number by half (100 to 50) all the way down to him not needing anyone:

REGAN
...
You will return and sojourn with my sister,
Dismissing half your train, come then to me.
I am now from home, and out of that provision
Which shall be needful for your entertainment.

KING LEAR
Return to her, and fifty men dismissed?
No, rather I abjure all roofs, and choose
To wage against the enmity o' the air;
To be a comrade with the wolf and owl --
Necessity's sharp pinch! Return with her?
Why, the hot-blooded France, that dowerless took
Our youngest born, I could as well be brought
To knee his throne, and, squire-like, pension beg
To keep base life afoot. Return with her?
Persuade me rather to be slave and sumpter
To this detested groom.

GONERIL
At your choice, sir.

KING LEAR
I prithee, daughter, do not make me mad.
I will not trouble thee, my child. Farewell;
We'll no more meet, no more see one another --
But yet thou art my flesh, my blood, my daughter;
Or rather a disease that's in my flesh,
Which I must needs call mine. Thou art a boil,
A plague-sore, an embossed carbuncle,
In my corrupted blood. But I'll not chide thee;
Let shame come when it will, I do not call it;
I do not bid the thunder-bearer shoot,
Nor tell tales of thee to high-judging Jove.
Mend when thou canst; be better at thy leisure;
I can be patient. I can stay with Regan,
I and my hundred knights.

REGAN
Not altogether so:
I looked not for you yet, nor [now] am provided
For your fit welcome. Give ear, sir, to my sister;
For those that mingle reason with your passion
Must be content to think you old, and so--
But she knows what she does.

KING LEAR
Is this well spoken?

REGAN
I dare avouch it, sir. What, fifty followers?
Is it not well? What should you need of more?
Yea, or so many, since that both charge and danger
Speak 'gainst so great a number? How in one house
Should many people, under two commands,
Hold amity? 'Tis hard, almost impossible.

GONERIL
Why might not you, my lord, receive attendance
From those that she calls servants or from mine?

REGAN
Why not, my lord? If then they chanced to slack ye,
We could control them. If you will come to me --
For now I spy a danger -- I entreat you
To bring but five and twenty: to no more
Will I give place or notice.

KING LEAR
I gave you all --

REGAN
And in good time you gave it.

KING LEAR
Made you my guardians, my depositaries,
But kept a reservation to be followed
With such a number. What, must I come to you
With five and twenty, Regan? Said you so?

REGAN
And speak't again, my lord; no more with me.

KING LEAR
Those wicked creatures yet do look well-favoured,
When others are more wicked; not being the worst
Stands in some rank of praise.

To GONERIL

I'll go with thee:
Thy fifty yet doth double five and twenty,
And thou art twice her love.

GONERIL
Hear me, my lord;
What need you five and twenty, ten, or five,
To follow in a house where twice so many
Have a command to tend you?

REGAN
What need one?