The easiest and most simple way to do this is to cave, and buy Pokémon Bank.
I assume you know that you can transfer Pokémon from Bank into Home, but I forgot whether that's a premium Home feature. If it is, add another month of Home onto the price.
One year of Bank (yes, year, there isn't an option for a single month as far as I remember) is $4.99.
One month of Home (if transferring from Bank is a premium feature) is $2.99.
If it's not a premium feature, it's free for 30 Pokémon, which I assume is more than enough to get all of your 'mons to where you need them.
So, if you want these Pokémon in your Sword save, it'll cost at most $7.98, and at least $4.99.
The less expensive, but more difficult method is hacking your Switch.
If you don't have the specific Switch needed to hack it, you are going to have to pay.
The website below is a website to tell you whether your Switch is hackable or not. https://ismyswitchpatched.com
If you can't find the serial number, it's that white tag on the same side as the USB-C port.
If your Switch is hackable, great! Just a bit of effort, and you'll have yourself a hacked Switch.
If not, oof. Cough up between $5 and $8 for Bank and Home.
However, there is another method for hacking the Switch that I'm not 100% sure on. I don't remember the name or anything about how difficult it is to pull off, but it allows for EVERY Switch, regardless of serial number, to be hacked. A quick Google search should give you the answer on that.
Happy transferring!