How can a single visualforce Page be used on the page layout of multiple object(s)?

We can move our VF code to a VF Component Creating and Using Custom Components.

We can then create two VF pages which each include the same component (the standard controller is then on the VF Page and we can use a custom controller for the component).

This architecture will allow us to keep our code in one place but use on two standard pages.

Hope this will help.