Its really not that complicated or convoluted.

1)
-You want a console to play 4 player mario kart, smash bros and mario party? Buy the base system.
-Want the ability to switch between TV and play on the go? Buy a base system.

2)
-Want a console to play on the go & prefer portability and battery over screen size? Buy a Switch Mini.
-Just want a cheap system to play the newest Pokemon, Mario and Zelda? Buy a Switch Mini (or later in the systems life, a Switch TV).
-Buying an entry level platform for a child? Buy a Switch mini.

3) Later decide that you want to play your Switch mini on your TV? Buy a controller and a dock. The Switch concept is very well intact, you don't have 2 consoles, you have one, all your games work & you didn't spend an additional $300.

The idea that the Switch only sells because of its hybrid nature is funny. What was the last Nintendo handheld that sold poorly? The 3DS in it's 8th year just sold neck and neck with the Xbox One last week. I'm shocked that people are actually advocating against this.

"Interestingly enough, about 30 percent of users play the Switch in handheld mode a majority of the time. In contrast, just under 20 percent of players keep the Switch docked most of the time." I'm in the latter group who almost exclusively play on TV but even I know there is a market for both a dedicated handheld and a late life TV box,

https://www.digitaltrends.com/gaming/nintendo-switch-handheld-vs-docked/

None of these points matter because the hybrid version is still available, if people want to play games like ARMS or Let's Go in the way you described than they will get the version of Switch that allows them to play them that way.

A handheld version of Switch is for people who prefer handhelds and think Switch is too expensive, too big and has too short of a battery life to suit their needs. For people like this they dont care that ARMS and Let's Go have console exclusive features.

But thats the whole point.The arguments for a mini are mostly that Nintendo needs a cheaper Switch.Making a mini version, that is trying to be cheaper, is not going to give it a bigger batterry because: A)Better battery means more expenses with that aspect, so it goes against lowering the price and B)You are trying to make it smaller, thus you would have less space for a bigger battery.Since battery tecnology hasnt evolved that much in last years, the only way for you to make the Switch consume less energy is to have more efficient chips, which will in turn increase the manufacturing cost of the mini itself.

See the problem?If you make a mini thats too "simple" but cheap, you will have to sacrifice so much of it, including functionality and battery, for it to reach an acceptable performance(since it needs to run switch games) AND price.But if you make a mini thats "premium", then you are losing its affordability.Its a dead end no matter how you look at it.

And I mean, if you want a cheaper Switch unit for those that think the Switch is too expensive right now, just look at the regular Switch.Its bound to have a price cut this year, and if its already selling at this rate at 300 dollars, imagine at 250 with one or two games bundled with it.Not to mention that retail shops can make even better deals.I think during the holidays there was a facebook deal that was selling the Switch at 230 dollars if Im not mistaken.

And I dont think anybody thinks that the Switch is too big.As I have already read somewhere, portable devices have grown in size these past few years, and even phones are getting to a size which they are barely "pocket friendly".Tablets are selling like crazy, laptops sell like crazy, and the Switch is selling like crazy.

I mean, you shouldnt need to look any further than the Switch to see that its being accepted everywhere.The rate that the Switch is selling is almost Wii-like, if not more.But different than the Wii, the Switch is getting a far better support, both from first and third party.Not only that, but the software sales will keep encouraging more third parties to join the party, and thus keeping the Switch more relevant than the Wii ever was(in the long run), and thus having far better legs.

Its easy to say that the Switch is missing some kind of market, but what evidence that you have that supports it?Not only that, but the Switch dosent have to sell to the whole gaming market in one year.Until the Switch drops to a price low enough to reach those that dont have a high income, they wont sell to them.But doing a mini SKU isnt the answer to that.Its lowering the price of the normal console as the years go by, much like the PS4 is doing right now.

And honestly, never seen people complain, outside of one and two, that the Switch is too big.The audience that does think that is extremely small and honestly irrelevant, and if a mini does launch and if indeed is the perfect marriage between price and functionality, its going to sell because its cheap, not because its purely a handheld device.

We still talking about same platform and same games, thats far more important than single concept.

We will know if it is official on next investors meeting, if they forecast beyond 20M.

Not needing a overclock for dock mode helps a lot in changing its form due not needing such heat dissipation. But I hope they go in smaller transistors direction. And can use it on regular switch as well.

I hope it comes with an official mini dock
with it, that also works on regular switch.

The only software I see problem on it is labo. It won't fit on cardboard models.
But seems that labo was not as successful as Nintendo intended, so, who cares..

Not as well as vita+3ds few years ago. Switch is not totally filling the market of sub 200$ hh dedicated gaming devices on Japan. It can always sell more. 

Yeah, but how much money is Nintendo printing with the Switch vs what they did with the 3DS?? It's such a healthy platform in its current form. It's a premium device that commands a premium for both hardware and software. I'm not sure how a cheaper, gimped version of the Switch will fare long-term. The 2DS didn't exactly set sales on fire...

Why would Nintendo not look into more ways to get more Switch's out there?

The 3DS was already cheap enough to make the 2DS redundant, as you said the Switch is Premium priced right now and obviously that limits its audience even if it is selling great right now. Beyond that, no one benefits from the reduced capcity of the 2DS but a Switch Mini's ease of portability and made for purpose form factor (e.i vita is far more comfortable to hold than the Switch) may make it the preferred platform for a proportion of people. And as said before it could encourage multiple platforms per houshold and even per user. 

If cost cutting is the main focus they're probably just go with the basic GBA/Vita form factor but I know a lot of people love the practical clamshell design of the 3DS

And the PSP's go slide up design could be great too (not great for control sticks though)