Hi Kamy,
Group, in the help topic you are reading, says you can group "objects" and applies to "objects" placed on a Sheet in Numbers.

The top row of three objects (the set will be familiar to most Canadians) are individual objects, as evidenced by the selection rectangles around the space taken by each.
Arrange > Group joins the three to act as a single object—clicking on one selects all three. They can be re-sized as a single object, retaining the proportions of all three, and of the space between them, moving the set to a new location, duplicating the single object, etc.
As to your 'survival' question, it depends...
Simple data tables transfer quite well between Numbers and Excel and back again. When you start adding specific formatting and formulas to the mix, the accuracy of the translation depends on whether those formats and functions are supported in both applications, and whether features are supported in the same way on both sides of the divide.
The only formula in my example above is the one controlling the appearance of "show" in cells in column B:
IF(A$2,"show","")
Excel certainly supports IF, but I don't know if it supports checkbox formatting for cells, or if it does, if that formatting is transferable between Numbers and Excel.
If Excel does support checkboxes, will A$2 be sufficient test for the presence of the boolean value TRUE in the cell, or does that have to be revised to IF(A$2=TRUE,... ? Does the translator know that?
Both Numbers and Excel support filtering of rows. Is their support of this sufficiently similar to allow the filtering in one application to be transported to the other intact?
Only testing will tell.
Regards,
Barry