How to assign template to repeatable group?

[Kaylakaze]

I have a huge form that has many repeatable groups in it. For most of them, the default table structure works fine, however, some others have 12+ fields that need to be filled out. The standard table form obviously won't work well with this many elements, and the list view seems bad for repeatable groups in general. I understand about editing the template files and whatnot (I think) but if, for example, I duplicated the default_repeatgroup_row.php and modified it so that each row is rendered as a 4x3 table, how would I assign that to the group I need to assign it to without affecting any other groups in my form?