Transfer articles from one site to another - what threatens from the point of view of SEO?

Question

Google

There is an indexed site No. 1 with an age of 6 months, attendance 1.5 unique per day.
I want to transfer 6 articles from it to another site No. 2, almost 4 years old and visited by 10-20 uniques per day.
Nothing terrible for the site number 2 will not be the same?
Site number 1 I will close then.

Answer 1

Transfer everything and put a 301 redirect.

Answer 2

If the first site is about tractors, and the second is about dental treatment, then it’s not necessary.
If both are about tractors, you need to check whether those 6 articles will be similar to the old ones.
If both about tractors and articles are not similar, then as Zooks wrote - 301 redirect and wait for reindexing in popular search engines, then you can delete it.