Pages - Apply existing Paragraph Style formatting to Pasted text

I am new to Pages and I am struggling on finding an 'easy/quick' way to apply ALL saved Paragraph styles to text that I am pasting into a new document.

I have 2 Pages documents, the first is a blank template with all my paragraph styles set and saved, and the other is a document containing all of my text (but the formatting of paragraph styles settings are different).

I am trying to copy and paste all my text from the second document into the first, and automatically apply all the styles I have saved in that 1st document... but I am struggling :-(

I have tried 'COPY' and then 'PASTE & MATCH STYLE', but all that seems to do is paste all the text into the 1st document and format it with whatever paragraph style is currently selected in that first document. As you can see in my first screen shot... this pasted and formatted all the text as 'HEADING 2'....

When I try just COPY and PASTE, the text is pasted into the first document and keeps the original paragraph styles, but the formatting of these styles matches the original document.. and not the ones I have saved in the 1st. As seen in this screenshot.... Heading 2 has an Asterix next to it to indicate the formatting isn't per what has been set within the doc....

I have tried highlighting one of the paragraphs, changing it to the formatting I want and selecting 'Update' styles. but this only updates that current text and not the rest of the docyment.

I know I can manually go through the document and amend each paragraph setting to what I want once I have done the paste.... but surely there is a better way of doing it????

Any advice would be GREATLY appreciated... my document is 800 pages long and I don't fancy having to do it manually!

one suggestion was to try selecting all text, and changing Character Styles to None to remove all these formatting overrides, but it had no effect.