How can I identify duplicate words & numbers with different sheets in numbers?

One quick way to locate duplicates is to just search (command-f).

In Numbers that will search across all tables on all sheets in a document.

There is no problem searching for a Chinese company name plus stock listing number, e.g. something like 遠雄5522, though you will need need to take care that you put the same number of spaces in the search box as you have in the cells. One way to do that is to copy-paste a value from a cell into the search box and use that as the basis of your search for duplicates.

SG

Not sure I understand exactly what you are trying to do in the example you give.

Yes, Numbers has the VLOOKUP just like Excel, and its more modern equivalent, XLOOKUP.

Also, keep in mind that you can filter for duplicates in a column.

SG

I can't think of an easy way to identify all duplicates across all sheets but it wouldn't be too hard to identify the cells on a particular sheet that have duplicates elsewhere (on the same or other sheets). But before getting to that, is it the entire array/table of cells you want to compare for duplicates or do you want to compare row-by-row or date-by-date or column by column?