How would be the way to define different view templates when displaying a page in a contentarea????

For example, I would like that page type pt1 would render as template1 in a contentarea of page type pt2, and at the same time renders 

as template2 in a contentarea of pagetype pt3.

           |  template1 in a contentarea of pt2

pt1 ->  |

           |  template2 in a contentarea of pt3

I solved it including another page pt4 that inherits from pt1, so:

- pt1 renders always with template1 in contentarea of pt2

- pt4 renders always with template2 in contentarea of pt3

Is there a better way to get this working without using inheritance??? Do you think it's a good or a silly solution to solve this problem???