Name check / data validation formula

Hi Folks,
I have a new question about validating or identifying incorrect data.
I have uploaded an example spreadsheet.
I have about 100,000 lines of such data to work with.
So, I would like to know if anyone can provide me a formula that I can copy and past down to solve my problem.

The issue is this:
The last name of the Actor in cell F4 must match with the last name of data in cell G3.
If the names match, in cell H3, it needs to return "OK" else "NO"

The formula would then have to skip F5:G6 and search for a data match in cells F8 and G7
in the example provided, there is a typo in the last name in cell G7. So, the returned answer in H7 will be "NO"

I am looking for a formula, that I can copy and paste down for about a 100,100 such entries - to search for typos and name discrepancies.
All the entries are separated by the two blank cell spaces.

Any assistance would be appreciated.
Thank you
Doofus